THE WIND WAS BLOWING hard at noon on Saturday, April 20, when Avishek Sengupta and his five teammates gathered near the starting corral of the 2013 Mid-Atlantic Tough Mudder. Part of a throng of more than 13,000 obstacle racers who would hit the course in staggered waves that weekend, they sang the national anthem and listened to a speech about how their efforts would serve as a defiant response to the Boston Marathon bombing a week earlier. "This is how you fight back!" the starter shouted into his microphone. Sengupta and his friends and an adrenaline-charged crowd of strangers jumped and whooped. "Leave no Mudder behind!" the starter yelled, then counted down from ten and blew his whistle. In a haze of orange smoke, they were off.

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The morning had begun just after eight in Columbia, Maryland, a leafy suburb halfway between Washington and Baltimore, at the parking garage of an Internet marketing firm called WebMechanix, where five of the six teammates worked. Sengupta, whose friends called him Avi, was one of the first to arrive. Soon he was joined by a coworker named De'Yonte Wilkinson and their boss, Arsham Mirshah, who had launched WebMechanix in his father's townhouse. The other three teammates, Josh Muskin, Sam Rahimi, and Kimberly Keen—the only one in the group who didn't work at WebMechanix—showed up about a half-hour late. They piled into two cars for the 90-minute drive to Martinsburg, West Virginia, where they would hop a shuttle to the Peacemaker National Training Center, a private firearms range in nearby Gerrardstown that Tough Mudder had transformed into a ten-mile track strewn with its trademark obstacles. Avi made himself comfortable in Wilkinson's gray 1997 Honda Civic. If he was nervous about participating in what Tough Mudder advertises as Probably the Toughest Event on the Planet, he didn't show it. Rahimi remembers that Avi was "chilling in the back of D's car with his shoes off, just good to go."

They all had hangups about certain obstacles—Mirshah had been taking cold showers to prepare for the ice bath at one called Arctic Enema, and nobody was excited about getting zapped at Electroshock Therapy, where contestants run through a field of dangling live wires—but they were all in good shape, including Avi, who had worked especially hard to be there.

For Avi, the oldest of the group at 28, doing a Tough Mudder was the culmination of 16 months of dogged self-improvement. He had always been stocky, but in his post-college years, long hours hunched over a keyboard combined with a fast-food diet had made him obese. Avi stood at five foot six, and he'd hit his maximum weight of roughly 215 pounds in 2011 while living in Philadelphia and working at Dreamscape, an Internet marketing firm founded by his lifelong friend Daniel Gemp. In January 2012, he decided to change his ways.

He started eating better and jogging. He ran a mile or so at first but added distance bit by bit until he could run for an hour without stopping. On weekends, he would go home to stay with his parents in Ellicott City, which is near Columbia, and climb at EarthTreks, a rock gym where he'd been an instructor since high school. Within two months he'd lost 25 pounds. In March 2012, he moved back to Maryland, took the job at WebMechanix, kept up his training, and occasionally gave in to old food temptations. He had a particular weakness for football-size Chipotle burritos.

Still, Avi kept shedding pounds, and by the day of the Tough Mudder he'd slimmed to a thick-necked 165. For years, Avi had worn a scruffy goatee and styled his thinning hair with gel. As part of his makeover, he started shaving his head and face. Gemp, who had known Avi since kindergarten, was astonished by the transformation. "He looked kind of badass," Gemp told me. "Like the badass version of Avi."

IT WAS THE NEW AVI, dressed in red shorts with black stripes, a black T-shirt, and a pair of bright yellow sneakers—which his friends described as "hideous"—who traveled to West Virginia, predicting that he would beat everybody in his group. (In Tough Mudders, participants aren't timed, and there are no official winners, but people who head out together often race each other for bragging rights.) The teammates had missed their assigned start time by about two hours, but Tough Mudder officials allowed them to jump in with the noon group. Being late had an advantage: the temperature had climbed into the mid-fifties after a chilly morning in the low forties, and the sun was shining.

Keen tore her pants on the first obstacle, a low crawl underneath barbed wire called Kiss of Mud, but the rest of the team were unfazed. Muskin playfully slapped a dirty palm print on Avi's shiny scalp, and they all moved on together. A few minutes later, they were slogging through Mud Mile, a series of trenches filled with knee-high water. Mirshah scrambled onto a slippery berm and attempted to reach down to help pull Avi out of a trench, but Avi was fine and bounded past him without a glance. At the third obstacle, a 15-foot-tall haystack called Bale Bonds, it was Avi, the climber, who reached the top first and offered a hand to the others.

A half-hour in, the teammates ran into their second traffic jam of the day: a human bottleneck at a water obstacle called Walk the Plank. The group chatted as they shuffled along with about a hundred other participants toward a near vertical wall of two-by-sixes that rose to a platform 15 feet above a man-made pool of muddy water that was roughly 40 feet wide and 15 feet deep. When they reached the top, they would have to leap in and swim to the other side.

The mood was less relaxed on the platform, where the teammates became separated from one another amid a mass of nearly 30 other participants jostling toward the edge. "It was nerve-racking," Rahimi told me. "There was a lady with a bullhorn yelling something. Even when I got up there I couldn't tell what she was saying." Muskin heard someone counting people off at the top but said there was also someone at the bottom trying to do the same thing. "They were not working together," Mirshah recalls, adding that he didn't hear any directions at all. "I had no idea there was someone up there directing. I had no idea how many people were supposed to go at once."

Rahimi reached the edge first. Worried that the platform might tip over, he leaped for the relative safety of the water as soon as he heard someone yell "Go!" Someone else counted down, and Muskin jumped, alone. When it was Mirshah's turn, he peered over the edge and considered climbing down. Instead, he took a deep breath and jumped. Keen followed.

Wilkinson reached the top of the platform on Avi's heels. "I remember Avi asking me if I wanted to go before him, and I said, 'No, you go first,' since he got up on the platform before I did," Wilkinson said. "And I remember he kind of calmed down a little bit, and then he jumped in."

Nobody realized it at first, but Avi didn't resurface after his plunge. He was underwater and sinking to the bottom, passing out at some point, for reasons that are still unknown. When he was next seen on the surface, at least eight and a half minutes after he'd jumped, he would be unconscious and in the arms of a rescue diver.

Four months later, in August 2013, when I visited the teammates at the WebMechanix office in Columbia, it was still difficult for them to discuss that moment. They described the horror of seeing Avi's bloated abdomen and the deathly hue of his skin. "He looked like a crash-test dummy," Mirshah said, his voice trembling. "His head was off to the side with white foam coming out. I was bawling."

Mirshah paused to regain his composure.

"Every part of us wanted to believe that he was pulled out in time," he said, "but the logical side of us knew that he wasn't."

ON THE AFTERNOON of April 20, Avi's mother and father, Mita and Bijon Sengupta, were at a relative's home in Bozman, on Maryland's Eastern Shore, hosting a bridal shower for Avi's younger sister, Priyanka. They were just about to have lunch when Mita's cell phone rang. "You know sometimes when you hear something, and your heart starts pounding so hard that you can't even hear?" Mita asked me, sitting in the airy living room of the family home in Ellicott City. "All I heard was, 'Is your son Avishek Sengupta? There has been an accident.'"

Minutes later the family was racing to Inova Fairfax Hospital, in northern Virginia, where Avi had been airlifted from Martinsburg. They were greeted at the hospital's entrance by a social worker, and they knew what that meant. "The only time they send the social workers is when they want to prepare you for the bad news," Mita said, tears welling in her eyes.

Avi had always been a great kid. Mita and Bijon couldn't remember a single time he'd bad-mouthed anyone. As Mita recalled, "Even when I would say something about someone, he would say, 'You don't know, Mom, maybe he had some reason.'" Avi's coworkers at WebMechanix concurred, saying they never once heard Avi use profanity. He was the guy whose hearty laughter filled the office, who stopped by everyone's desk to say hello before starting his day.

Mirshah's only complaint—a good-natured one—was that he could never get Avi to kick back with a cold draft during beer Fridays at the office, where there was always a kegerator filled with Shock Top. Avi never drank or smoked. Uninterested in college partying, he had moved home from the Towson University dorms after his first semester in 2003 and spent a lot of his free time playing Cranium and Trivial Pursuit with his parents and Priyanka, who is now 23. Approaching 30, Avi was in no hurry to move out. "He loved his family," Mita told me with a smile. "He liked hanging around us."

In the year before Avi's death, the Sengupta family grew even closer as they prepared for Priyanka's wedding. Late-night eating had always been a family ritual: Mita would bake a frozen pizza or warm some leftover Indian food, and everybody would stand around the kitchen island, snacking and discussing the day. But when Avi moved home from Philly in late 2011, he'd begun dieting and exercising, and he wasn't up for snack sessions anymore. Using the prospect of Priyanka's wedding photos as a motivator, Avi convinced Mita and Bijon to go on a diet, too.

Mita first remembers hearing about Tough Mudder at the dinner table in February 2013, when she reminded Avi to mark Priyanka's bridal shower on his calendar. He told her he couldn't come, because he was running the course with his coworkers that day. Mita was disappointed, but she was happy to see his enthusiasm, so she let it go. Bijon, who was normally very protective, decided not to discourage Avi either. "He was getting into better shape, and that was a positive thing," Bijon said. "He was really looking good."



DURING THE FIRST 24 hours at Inova, the waiting room grew so crowded with Avi's family and friends that the security guard had to ask people to leave—there wasn't enough room for other patients' relatives. In the ICU, Avi had a pulse, but there was no brain activity. "I just saw him, and it wasn't him," Bijon said, his voice barely above a whisper. On the afternoon of Sunday, April 21, Bijon told the doctors to take Avi off life support. "We left the room, and it took a few hours," Bijon said. "His heart was very strong."

Suddenly, Mita and Bijon had to make plans for both a wedding and a funeral. Looking back, they're grateful for the distraction of endless errands. They were also buoyed by the turnout at Avi's memorial service on April 24, when dozens of young people they'd never met came to tell them how Avi had touched their lives.

Whatever relief they felt was overshadowed by the dawning sense that something had gone terribly wrong in West Virginia. In the immediate aftermath, Mita and Bijon were in a state of shock, and they had no time to give any thought to Tough Mudder's official statement on the matter: Avi's death had been a tragic accident, a fluke that couldn't have been prevented, despite the presence of more than 75 safety personnel on the course. That view was bolstered for the public in late May, when the Berkeley County sheriff's office released its incident report, calling the death an accidental drowning. The report made it seem unlikely that Avi had been jumped on by a fellow Mudder, stating that there was no evidence he was "struck or suffered some other contact to his body prior, during or after entering the pool area."

But the report also quoted witnesses who said the response time by Tough Mudder's safety officials was inexplicably slow. One of them, a spectator named Michael Cardile, had called Inova on the day of the incident and asked the ICU nurse to give his number to the Senguptas. When the family called a few days after Avi's death, Cardile told him that he'd seen Mirshah pleading with lifeguards for several minutes before they ordered the rescue diver in. "He was really, really mad," Bijon said of Cardile. "That made us think that something definitely went wrong."

By the time the sheriff's report became public, Mita and Bijon had also spoken in depth with Avi's teammates. The accounts prompted them to hire lawyers to prepare a multimillion-dollar gross-negligence suit against Tough Mudder and a company called Amphibious Medics, which helped manage safety procedures at water obstacles like Walk the Plank. At press time, nothing had been filed in court, in part because the Sengupta family and Tough Mudder were in talks about a possible out-of-court settlement.

Soon after Avi's memorial, Mirshah mustered the courage to pay his respects at the Senguptas' home. He told Avi's parents that he and the others were ashamed that they hadn't done more to help on the course that day. Bijon and Mita reassured Mirshah and later invited the rest of the team to the house. There, the teammates told them disturbing details about the lack of urgency displayed by a rescue diver who was assigned to the Walk the Plank pool, and how a safety official on the shore had argued with Mirshah, challenging his assertion that Avi hadn't resurfaced. Last August, at the WebMechanix office, the teammates recounted the same details for me.

Wilkinson was the first to sense that something was wrong, noticing soon after Avi went in that he hadn't come up. Within 30 seconds, he said, he began trying to get Mirshah's attention, gesturing at the water and shouting, "Where's Avi?" Mirshah had seen Avi jump but was distracted by the sight of a lifeguard dragging someone else to shore. For a second he thought it might be Avi, but it wasn't. Moments later, when he looked back up at the platform, Wilkinson was in a full-blown panic.

"I hear De'Yonte yelling, pointing down to the water," Mirshah recalled. "And I don't know what he said, so I walked a little bit closer up to the edge of the pool to hear him, and I thought he was saying, 'How deep is it?' And I'm like, 'It's deep, man. Just get in. It's cool, it's deep.' Then I listen closer, and he's yelling 'Avi! Avi!' And as soon as I hear it, his name, 'Avi,' I'm like, Oh shit. I look around. No Avi. And then it hits me—he's saying Avi's still down there."

Mirshah ran to the first lifeguard he could find. "I'm like, 'Hey, my man! We got someone down there! My friend's still down there!' And his first response to me was, 'Are you sure?' " The lifeguard peppered Mirshah with questions: Did you see him go in? Did you see him come out? People were yelling Avi's name, but Mirshah said that when it finally dawned on the lifeguard that Avi might be submerged, he wandered off "aimlessly," as if he were looking for someone else.

All the while, the lone rescue diver was sitting on the edge of the pool without his fins, tank, or mask on. When the lifeguards ordered the diver into the water, more than two minutes after Avi jumped, "there was virtually zero rush," Muskin said. The diver, Travis Pittman, who was subcontracted for the event by Amphibious Medics, could not be reached for comment. But he later admitted to the Berkeley County sheriff's department that he was not geared up at the time of the incident and that he initially went into the water with only his mask. "Mr. Pittman said this is not normal protocol for safe diving," Sergeant Ted Snyder, the investigating officer, wrote, "but in the interest of time, he elected to enter the water to conduct a quick search."

Frustrated, Rahimi dove into the pool himself. "Among the panic and the cold, I realized I couldn't go very far without having some serious trouble," he told me. And so Rahimi turned back and watched helplessly with the others, wet and shivering, as the minutes dragged on.

EVERY STRENUOUS outdoor pursuit carries risk. In a typical year, roughly 40 people die at lift-served ski areas, and there are a handful of deaths and hundreds of injuries among people who do marathons and triathlons. Whether obstacle challenges are more or less dangerous than other sports is difficult to say, because there's no governing body for these events and nobody keeps precise statistics. But an informal survey conducted by Outside indicates that, per participant, obstacle racing is actually less likely to end in death than marathons, triathlons, recreational skiing, or bicycling.

Obstacle challenges are operated by private companies large and small—among them Tough Mudder competitors like Spartan Race and the creators of smaller, local events like the Freak 5K—who stage them for profit and require participants to sign standard liability waivers. What we know about casualty rates is gleaned mainly from news reports that appear when something goes wrong at a race. After Avi's death last spring, Ryan Krogh, an editor at Outside, surveyed the industry and found a few other deaths (including two from heatstroke at a 2011 Warrior Dash outside Kansas City) and a host of serious injuries, including several cases of paralysis resulting from falls or dives. Other common mishaps include hypothermia, lacerations, electric shocks, burns, and broken bones.

At the Tough Mudder where Avi died, the Martinsburg City Hospital's emergency room was swamped with event participants that weekend. They treated two heart attacks, orthopedic and head injuries, and multiple cases of hypothermia. Jennifer Andersen, a 40-year-old mother of two, was admitted for complications resulting from a near drowning. Andersen passed out from exertion on an obstacle called Pirate's Booty. She fell about 15 feet, colliding with another participant on the way down and landing face-first in a pond. She was rescued by fellow participants.

The response by Tough Mudder in the wake of Avi's death has been consistent: We are heartbroken by this occurrence, but we're also proud of our safety record. "As organizers, we take our responsibility to provide a safe event to our participants very seriously," company CEO Will Dean said in a press release issued the day after Avi died. "Tough Mudder is devastated by this tragic accident." The release went on to say that the West Virginia Tough Mudder "was staffed with more than 75 ALS, EMT, Paramedics, water rescue technicians and emergency personnel" and that Avi was "the first fatality in the three-year history of the company, after over 50 events with more than 750,000 participants." Just two months earlier, in February, Dean told Inc. magazine, "Statistically, it's amazing. You take that number of people, and if they were sitting at home that day, statistically, we should have had a few heart attacks. I have to tell the team, it's coming. We have to accept that it's going to happen at some point and work to ensure it never does."

With litigation a possibility, Dean isn't commenting further, and Tough Mudder declined my requests to see internal documents relating to safety procedures. Company officials did invite me to Tough Mudder's Brooklyn, New York, headquarters last summer to discuss safety issues, and I was told repeatedly that Tough Mudder is and always has been committed to participant safety. "We did everything we could," chief operating officer Don Baxter said about Avi's death, adding that "it's impossible to remove risk entirely from these events."

Mario Vittone, a retired U.S. Coast Guard rescue-swimmer instructor and aquatic-risk-management consultant based in Virginia Beach, sees it differently. Vittone has been hired as an expert witness by the Sengupta family's lawyers. He argues that Tough Mudder could have done much more to mitigate the risks in West Virginia, and that what Dean calls the company's "amazing" safety record may have been the very thing that blinded it to inadequacies.

"Mistaking the lack of failure for success is a really common human error," Vittone explained. "It's like texting and driving. If the teenager texts, he's just learned that he can do it and not get in a wreck," and so he's likely to do it again.

Tough Mudder declined to address this and other criticisms made by Vittone. Baxter told me that Tough Mudder's safety record is important to its branding but that safety isn't just about marketing for the company, which will net approximately $100 million for 2013. "Part of what makes Tough Mudder different from much smaller mud runs is that we have the resources to be able to invest in making things like these obstacles better, and in making sure we've got as good a quality of medical care as possible," he said. "We just have a duty of care to everyone who comes through."

Ben Johnson, Tough Mudder's communications director, emphasized that the company spends hundreds of thousands of dollars annually on safety training for employees and is projected to incur "significantly more than $4 million" in external event-safety costs in 2013.

From Vittone's perspective, though, it doesn't matter how much money Tough Mudder spends if it fails to apply military-grade risk management to what the company markets as a military-style obstacle course "designed by British Special Forces."

"The training done by elite military combat professionals involves a lot more than setting up an obstacle course and sending the troops in," Vittone wrote on April 23 in a widely circulated blog post. "They go through months of buildup and monitoring, the training is extremely well supervised, and their emergency response plans are well thought out, practiced, and proven. By comparison, an event like Tough Mudder is a free-for-all."

BEFORE THE INCIDENT in West Virginia, Vittone had never given much thought to Tough Mudder. Intrigued by news stories about Avi's death, he began searching for participant videos on YouTube. As he studied the deployment of safety personnel and the crowd-control measures used for Walk the Plank at various Tough Mudder events, his immediate reaction was harsh. "This isn't planned out," he told me. "This is hoping. This is throwing people in the water, throwing out a couple of lifeguards or some guys in kayaks, and hoping for the best." When a video of the entire West Virginia incident at Walk the Plank appeared online last June, shot by a participant named Brett Brocki, Vittone's convictions hardened. "There didn't appear to be any standard operating procedures," he said. "Even within the few minutes that the video shows, there's a difference in the way people enter the water from the first second of the video to the last minute of the video."

Something as simple as managing the way Tough Mudder participants enter and exit a muddy pool may seem trivial, but Vittone says that military-style SOPs, or standard operating procedures, are a vital element in risk management, because they help control variables, ensuring that the only risks posed by a hazardous activity are the ones that can't be eliminated.

In the case of Walk the Plank, where participants plunge into cold water over their heads, it would be impossible to eliminate the inherent risk of drowning. But Vittone says that properly designed SOPs could stop many other calamities: collisions between participants in midair or in the water, lifeguards getting distracted by disorganized crowds, or a participant drowning without being seen. In Vittone's opinion, all of those additional human-error risks were in play on the day Avi drowned, and those factors combined to make an effective rescue impossible.

When I asked Vittone how he would reform Walk the Plank, he said it was simple: he'd shut down the obstacle entirely. "Deep, murky, cold water above your head is an unacceptable risk, and it can't be effectively managed," he said, "particularly when there's no value added except for fun." When I pressed him for a more compromising position, he said, "I would at least expect them to follow the same safety protocols that are followed at water parks with clear water and ten-year-olds—one person in the pool, one person out."

If it were up to him, Vittone said, he would require eight divers at Walk the Plank—two separate teams composed of a diver, a backup, a dive tender, and a dive master, rotating frequently to prevent fatigue and inattention. When Avi drowned, Travis Pittman was the only diver on hand.

Vittone conceded that Tough Mudder could probably reduce risk at Walk the Plank to an acceptable level, but doing so would create long waits. "The list of things I would put in place are doable, but then you can't run 20,000 people through it in a weekend, not without building five of them," he explained. "So it's one of those things: to do that safely, you can't do it fast, and therefore I would suggest against it."



FOR NOW, TOUGH MUDDER has no plans to remove Walk the Plank from its obstacle lineup. Baxter told me the company applies "a rigorous data-driven approach to making sure that risk is minimized," and the data shows that relatively few injuries occur at Walk the Plank. People get hurt more often at obstacles like Balls to the Wall, which requires participants to climb over a 12-foot vertical wall, leading to many twisted ankles and the occasional broken leg. To reduce risk, Tough Mudder added wall cleats and spread mulch at the base to soften landings.

Baxter couldn't think of any modifications they'd made to Walk the Plank based on injury data in the three years leading up to Avi's death. Sitting in Will Dean's office at the Tough Mudder HQ, he had a sheaf of papers spread out before him, including schematics of obstacles and metrics showing coursewide and obstacle-specific injury data. "Walk the Plank does not feature in any of these," he said. "I hazard to say it's not in our top ten in number of injuries."

While Tough Mudder has not admitted to any fault in Avi's death, the company has taken significant measures in the months since it occurred to improve safety management at Walk the Plank. In midsummer of 2013, it altered the description of the obstacle on its website to remove this sentence: "Don't spend too much time pondering your leap—squadies at the top of the platform will chew you out, or worse, push you into the freezing depths below." Ben Johnson told me that this comment was "clearly made in jest" and "not something we did on-site." But Amy Cohen, a teammate of Jennifer Andersen's, says that when she hesitated at the top of Walk the Plank, a Marine volunteer told her, "If you want, we can push you." A moment later, she says, someone shoved her hard from behind. She hit the water in a panic and had to be rescued. (As it happened, the change in the description on the site was only temporary—the old language was restored in September.)

More substantive and lasting changes have involved implementing a standard construction plan for Walk the Plank and a carefully managed deployment of safety personnel. Prior to Avi's death, standards appear to have been inconsistent. A quick search online turns up photographs of at least half a dozen iterations of Walk the Plank's construction design, with as many variations in the arrangement of safety workers. One of the first meaningful steps Tough Mudder took, according to Baxter, was to standardize the design and create a new set of SOPs. "It's part of us analyzing how we can improve on the back of West Virginia," he said.

In the current design, participants climb to the platform in single-file lanes separated by handrails. Up top, there are places for volunteers to stand, sectioned off by two-by-fours. Each volunteer is responsible for two lanes and actively directs jumpers on either side of his position. In the pool below, there's a one-to-one ratio of lanes to lifeguards. Before allowing each participant to jump, the volunteer on the platform communicates with the lifeguard below to make sure the previous jumper has resurfaced and cleared the lane.

Tough Mudder's improvements reflect suggestions made by MedPrep Consulting Group, a New York firm hired in May 2013 to do a full audit of the company's medical services. Stu Weiss, MedPrep's CEO, is an emergency physician who has served as medical director of the New York City Marathon and the New York City Triathlon. He said he was impressed by Tough Mudder's eagerness to improve. "Obstacle races are sort of like running was 15 years ago," Weiss told me over coffee one afternoon. "If you look at races ten years ago, all the big races, even the New York City Marathon—the medical delivery system was Band-Aids and Vaseline. Over the past ten years, it's really developed into something where now we deliver state-of-the art care." These days, major marathons and triathlons have mobile triage centers on-site, staffed with ER doctors and nurses. Weiss said he plans to bring that standard of care to Tough Mudder, and he hopes other obstacle-challenge companies will follow his lead.



WITH VITTONE'S comments in mind, I asked Weiss about the importance of SOPs. He said they're crucial, adding that he personally reviewed and improved existing SOPs for all Tough Mudder obstacles as part of the spring audit. Safety personnel and volunteers now receive "obstacle cards" detailing the actions they should take during an emergency. On the morning of the first day of each two-day event, volunteers and staff run through real-time drills to ensure they understand their roles.

At the Tough Mudders Weiss had attended as of last August—Pittsburg, Philadelphia, and Buffalo—he found that Walk the Plank had been set up exactly the same way each time. There had been a one-to-one ratio of lifeguards to lanes, and the volunteers on the platform were in constant communication with the lifeguards below to make sure the lanes were clear. Weiss said he emphasized order to volunteers and safety staff: "You do not let the next person go until you see a person jump, come up, and swim to shore." There was always at least one diver by the pool in full gear, ready to hit the water. A second diver had to be nearby, though not necessarily geared up. Johnson confirmed that Weiss's description matches the new written SOP for Walk the Plank.

Later, when I looked at participant videos from the events Weiss mentioned, there were a few discrepancies between the efficiency he described and what I saw. For example, one video from Pittsburgh shows four lifeguards watching nine lanes. In videos from all three events, there is no discernible communication between the platform volunteers and the lifeguards below.

But in Avi's case, the issue is the standards used on the day he ran the course. Video evidence and witness descriptions seem to support Vittone's assertion that there were no SOPs in place on April 20. Weiss told me that he had not discussed the West Virginia incident in detail with Tough Mudder and had not seen the video of Avi's jump and the subsequent rescue effort. So I pulled out my laptop, and we watched two of the three videos supplied to the sheriff's department.

In the first, a wave of jumpers plunges in, and Avi steps to the edge of the platform. By my count, there are 27 other people on the platform with him. A uniformed Marine with a loudspeaker to Avi's right, on the far edge of the platform, begins a countdown from three, then breaks off and looks down at someone on the ground. Avi looks in the Marine's direction and backs away from the edge—waiting, perhaps, for instructions. Then the Marine yells, "Line up! Three, two, one, go!" A man to Avi's left leaps, and then Avi steps off, left foot first. Arms above his head, he plummets into the water. Five others jump on the same count.

A sixth jumper, a brunette woman in a red tank top, goes off a split second after Avi, a half-step to his right. Rather than look down to ensure the pool is clear, the Marine with the loudspeaker works his way into the middle of the crowd atop the platform and counts down again, sending off another group of five.

At 59 seconds into the first video, Avi has been submerged for 14 seconds, and his teammate Wilkinson clearly knows something is wrong. He starts pointing down at the water. A whistle blows to halt jumpers while a lifeguard helps a struggling swimmer to shore. By now, Wilkinson is pointing frantically at the water, shouting, "Sham! Where's Avi?"

Three more people jump. Then another and another. Fifty-five seconds after Avi's jump, Mirshah's voice bursts in—"Hey! Hey, my man!" Five more people jump.

When Pittman, the rescue diver, finally gets into the water—two and a half minutes after Avi jumped in—he does not have his mask on or a regulator in his mouth. Pittman swims out until he's beneath the center of the platform, then passes his mask up to a lifeguard on shore, ostensibly to have it cleaned. Thirty seconds later, still with no mask, Pittman starts yelling at frustrated participants, including Rahimi, who'd begun diving into the water to search on their own. Twice he yells, "I don't need anybody else in the water!" followed by, "I'm a rescue diver, back off!" Four minutes after Avi jumped, the diver descends for the first time. Wilkinson can be seen pacing on the platform above the pool, hands on his hips, flanked by three Marines.

Weiss's reaction to all this as he watched? His jaw hung slack. "Wow," he said. "That's nothing like I've ever seen."

I started to describe some of the things Avi's teammates told me that weren't clear in the videos, but Weiss shook his head. "In my emergency training, you have a minute, or 30 seconds—some short amount of time to find that person," he said. "Better to have a false alarm than to have somebody lying at the bottom for a long time. So there is not a delay, there is no questioning. Somebody says 'My partner didn't come up,' they clear the event. In the divers go."

I started to ask Weiss how he would react if he were to attend a Tough Mudder and witness a situation similar to what he saw in the videos, but he stopped me short.

"That would not happen at an event that I'm running," he said.

TOUGH MUDDER won't discuss its strategy for the Senguptas' legal action—nor will anyone from Amphibious Medics—but if the suit goes forward, its lawyers will likely stress the fact that Avi signed what Tough Mudder calls a Death Waiver, exculpating the company of liability for certain acts of "ordinary negligence" and "inherent risks," such as "inadequate or negligent first aid and/or emergency measures" and "errors in judgment by personnel working the event."

But the Boston-area firm Gilbert and Renton, representing Avi's estate, will likely argue that such waivers do not relieve Tough Mudder of the legal "duty of care" that exists whenever a business knowingly creates predictable hazards for the public. In the case of Walk the Plank, the predictable hazard—drowning—is clear enough. Hence the presence of a rescue diver and lifeguards at the obstacle on the day Avi drowned.

To prove that Tough Mudder breached its duty of care, the Senguptas' lawyers will need to demonstrate that a reasonable person would have managed safety at the obstacle differently. They believe Travis Pittman's slow response and his decision to neglect "normal protocol for safe diving" will constitute a major element of a wrongful-death complaint, and the video evidence showing the bungled rescue effort could be difficult to challenge.

The Senguptas' complaint extends to the larger problem of ineffective crowd control. Using Mario Vittone's testimony, the Senguptas' lawyers will argue that failure to control the flow of participants moving through Walk the Plank resulted in a disorganized environment in which it would have been impossible to carry out a rescue within the two-minute period required by industry-standard lifesaving manuals.

The Senguptas' lawyers will also question why the company failed to employ SOPs based on the recommendations found in the United States Lifesaving Association Manual and the American Red Cross Lifeguarding Manual. Both emphasize the need for SOPs that encourage constant vigilance by lifeguards, particularly during times of high activity.

David Judd, an event photographer who was stationed at Walk the Plank on April 20—from the time the first participants came through, at about nine in the morning, until the obstacle was closed after Avi's drowning—told me he witnessed 20 to 30 rescues over the course of the day. He said that the scene in the moments before and after Avi jumped was "chaotic." There was a large influx at midday, but the layout of lifeguards and volunteers did not change.

Judd, who says that in October he was barred by Tough Mudder from shooting future events, told me, "I just couldn't believe the amount of people jumping in that were resurfacing after jumping in and had to be immediately rescued; they were basically drowning." By the standards of the U.S. Lifesaving Association Manual, such a high volume should have triggered a "special operation mode," requiring extra lifeguarding resources or the closure of the obstacle. By keeping the obstacle open, Tough Mudder put volunteers and safety personnel under extraordinary pressure and increased the likelihood that they would fail to respond adequately to a report of a missing person.

In the event of a missing-person report in deep water with reduced visibility, the U.S. Lifesaving Association Manual requires immediate surface dives by lifeguards "spaced in a line close enough to see, or touch, each other while on the bottom," and the Red Cross Lifeguarding Manual recommends that they be equipped with masks and fins. On April 20, Pittman conducted his search for Avi alone while at least five lifeguards stood on the shore, with no masks or fins in sight. The pool may have been too deep and too cold to allow for effective surface dives anyway, and this is another fact that Tough Mudder's lawyers will have to contend with.



IN THE AFTERMATH of the incident, the comments sections beneath news stories covering Avi's death were often sympathetic, but there was also speculation about his level of fitness, with some critics making the claim that he must have drowned because he didn't know how to swim or because he didn't belong on the course in the first place.

Some argue that the injuries are the result of Tough Mudder's aggressive marketing, which has fueled extraordinary growth—from 20,000 participants in 2010 to a projected 750,000 in 2013—and expanded the participant base beyond the narrow segment of hardcore CrossFitters and other assorted gluttons for punishment. The injuries, they say, are the inevitable outcome when you invite desk jockeys into an elite arena.

The Senguptas' lawyers are unlikely to blame participants for what they see as Tough Mudder's failure to operate the event safely. They will likely argue that, as Tough Mudder's participant base exploded, the company prioritized good crowd flow over safety procedures, and that the protocols at Walk the Plank stayed the same—inconsistent and ineffective—until a fatality occurred.

The details of what happened under the water in the moments after Avi jumped in are unknown. Dr. Alan Steinman, a former director of health and safety for the U.S. Coast Guard, who has been hired by Gilbert and Renton as an expert witness, told me that the autopsy report shows that Avi had a contusion on his groin, suggesting (in contrast to what the sheriff's report said) that someone could have landed on him.

Under the surface, where the sunlight was blocked by the murky water, Avi may have become disoriented, causing him to swim diagonally instead of upward. If he did, he would have placed himself directly in the landing zone of other participants. A blow to the groin would have added to any aquatic distress Avi was suffering and reduced his ability to hold his breath.

His breath-holding ability may also have been reduced by a cold-shock response, which can happen anytime someone's head is submerged in cold water. (Steinman estimates that the water temperature that day was around 50 degrees.) Cold shock causes a sudden release of adrenaline and an increase in heart rate, and can reduce an average breath-hold time of one minute to just 15 seconds.

What we do know, unequivocally, is that Avi drowned. When cold water hit the back of his throat, it caused his larynx to spasm. As his vocal chords tightened, Avi would have panicked and attempted to inhale, which would have caused chest pain and may have triggered fear of death. His sealed larynx temporarily prevented him from taking water into his lungs but did not prevent him from swallowing large quantities, causing his stomach to bloat. Avi's brain quickly used up its available oxygen, and he slipped out of consciousness, causing his larynx to release. Though he was unconscious, his heart was still beating. He inhaled water. After three minutes, his brain cells began dying rapidly. For two additional minutes, there was a chance that he could have been recovered and resuscitated with only minor brain injuries. When five minutes passed, and Avi's lungs were still filled with water, his brain began to die from lack of oxygen. When the diver finally dragged Avi out, he had suffered catastrophic brain damage.



MITA Sengupta saw her son for the last time on the Friday night prior to the Tough Mudder event, just before she stepped out to visit with friends. When she came downstairs, Avi was standing in the kitchen.

"Hey, you look pretty!" Avi said.

"Thank you," Mita replied.

When she returned around midnight, Avi was already asleep. Bijon woke up early the next morning to have breakfast with Avi before he left to meet up with his teammates, but Mita decided to stay in bed another hour. She had a grueling morning of bridal-shower preparations ahead of her and wanted the extra sleep. Standing at the kitchen island where they'd shared so many late-night meals, Bijon told his son to walk around any obstacles that he didn't feel confident about. Avi promised to be careful.

"He was a big hugger," Bijon said, with an attempt at a smile, "so we hugged."

Mita's face lit up as she recalled how Avi would sneak up and give her "surprise hugs" in the morning. Startled, Mita would feign annoyance, and Avi would say, "One day you're going to miss my hugs."

Mita's strongest memory of Avi in the days before his death is a happy one. Priyanka, Mita, and Bijon had just returned from a craft store with vases and floral materials to make centerpieces. Avi had been out to a movie with a friend, and when he came home he found his family inundated in flower petals. Without any explanation, he walked over to Mita, took her arms, and started dancing and singing "Stayin' Alive." Priyanka captured the moment on video with her phone—Avi singing, Mita cracking up.

"That was his present for me," Mita said. "Two days after that he was gone."

When Avi reached the Tough Mudder parking lot in West Virginia, he sent Bijon a text that said "Reached." That was his last communication to his family.

The pain of Avi's death made Priyanka's wedding bittersweet. Avi was going to escort his sister down the aisle. He was also a groomsman and had volunteered to plan the bachelor party for Priyanka's fiancé, Seth Marple. The worst came after the wedding, when all the supportive friends and family had returned home. Priyanka and Seth left for a honeymoon cruise in the Mediterranean, and Bijon and Mita had to cancel the flights they'd booked to London for the post-ceremony vacation they'd planned with Avi.

"It hit us hard after the wedding," Bijon said, "when it was finally just the two of us."

"It's not being able to sleep. It's just crying at any little thing, feeling like you have an actual wound," Mita said.

We walked upstairs to see Avi's bedroom. Avi had been dead four months, but the way things were laid out gave the impression that he'd just been there. His box sets of "Magic: The Gathering" cards were stacked neatly by the door. His old stuffed animals—Tigger and Winnie the Pooh—were resting on the pillows of his twin bed. Against one wall, there was a wooden rack with a black Stratocaster and four acoustic guitars.

"Most of them have a string missing," Bijon said, allowing a chuckle. "You can strum it, but it will never play quite right." That's what their lives are like now, Bijon said.

A framed poster of Muhammad Ali throwing a right jab hung above the guitars, with the words, "I'm so fast that last night I turned off the light switch in my hotel room and was in bed before the room was dark." On the opposite wall, by a window, there was a James Dean poster with another quote: "Dream as if you'll live forever, live as if you'll die today."

Maybe these were the quotes that kept Avi moving in the early days, when he could barely run a mile without walking.

Elliott D. Woods wrote about skiing in Bamiyan, Afghanistan, in December 2012.