 -- When Ed and Suzanne Kristensen first heard about a Chinook helicopter being shot down in eastern Afghanistan on June 28, 2005, at first they feared for their Navy SEAL son Erik, who was deployed there at the time, but were reassured by a Navy friend that he likely wouldn't have been aboard.

"Someone said Erik wouldn't be on the helo,” recalled his mother, who goes by Sam.

It was a matter of seniority. Lt. Commander Erik Kristensen was a senior commander in SEAL Team 10 in Afghanistan and didn’t go on as many ground combat operations as those in the platoons under him.

"But he was on the helo," his mother told ABC News, as the family marked the tenth anniversary of Erik's death in Operation Red Wings last weekend.

A decade after the incident, Erik Kristensen, by many accounts an unconventional SEAL, remains a largely unknown figure in the public telling of one of U.S. special operations' most tragic -- but also most celebrated, for valor -- incidents in its history, despite bestselling books, websites and last year's hit movie "Lone Survivor.”

Kristensen was the one who organized a rescue mission after a SEAL reconnaissance team's leader, Lt. Michael Murphy, called for help well into a firefight in Kunar province's soaring mountains. As the task unit commander for SEAL Team 10, in which Murphy served, Kristensen decided to personally lead an assault force by helicopter to his last known location, where the younger officer had been tasked with finding a militia leader named Ahmad Shah.

But militants were waiting in ambush and shot down an Army MH-47E Chinook chopper as Kristensen and his men were preparing to fast-rope to the ground, killing all 16 aboard.

"There are some things you just don't delegate," Ed Kristensen said of his son’s fateful action, at times welling up with emotion. Even after a decade, his only child's loss "is still a very raw thing. You can't change it, you've got to live with it. But we think about it all the time."

Ed Kristensen is a retired rear admiral who had led the Navy's 1996 recovery of TWA 800 which had crashed off New York with 230 souls lost. The news about the chopper crash came while the Kristensens were, coincidentally, attending the retirement of a Navy diver in Norfolk who had served under Ed during the recovery of the passenger jet in the ocean. When the commander of Naval Special Warfare called him to say they were searching for Erik and the others, his father assumed the worst.

"With my experience with TWA 800, I knew what an aircraft crash does to people. We knew that we had lost him," the older Kristensen said.

Soon they learned that their son Erik was among those killed in action.

The fact that the task unit commander had personally led the mission with seven other highly experienced SEAL operators in broad daylight to rescue Murphy's team and kill Shah -- the leader of the "Mountain Tigers" local militia who Murphy had been sent to locate on the Pakistan border -- didn't surprise those who knew Kristensen.

"Erik did what any SEAL would do: go help SEALs in trouble," Navy Capt. Kent Paro, who led SEAL Team 10 at the time and was Kristensen and Murphy's commander in Afghanistan, told ABC News last week.

The only SEAL to make it out of the Red Wings incident alive, Navy Petty Officer Marcus Luttrell, went on to write the bestseller "Lone Survivor," which became a major motion picture of the same title last year.

Kristensen, 33, was portrayed in the film by Australian actor Eric Bana in a relatively small part. His unusual personality and fateful heroism has remained largely unknown in public compared to Luttrell and Murphy's legend, despite courageously leading the ill-fated rescue mission.

For his actions, Kristensen, who was on his first major combat deployment in Afghanistan, earned the Bronze Star with "V" (Valor) device. Murphy, 29, of Patchogue, Long Island, also was killed in action and received a posthumous Medal of Honor from President George W. Bush. The Navy named a guided missile destroyer for him.

A SEAL in Birkenstocks

"Lone Survivor" included a shot of Kristensen’s Birkenstock-clad feet trudging out of his quarters after Murphy's call for help is received in the tactical operations center in Jalalabad. Friends such as John Ismay, who wrote appreciatively about this detail in the New York Times last year, say that was a subtle tribute to Kristensen as a genuine "non-conformist," who didn't fit the Hollywood stereotype of coldly conservative SEAL warriors.

"That was the one part of the movie that I enjoyed. That's who Erik really was," said Jason Redman, who served in SEAL Team 10 as an officer with Kristensen at the time of the Operation Red Wings disaster and had once been in Murphy's platoon.

"Erik leaned to the left. He was liberal in his thinking. Guys gave him a lot of grief but he was witty about it," Redman, author of "The Trident: The Forging and Reforging of a Navy SEAL Leader," said in an interview.

Kristensen attended Washington's Gonzaga College High School. He rowed crew, played lacrosse and majored in English and French at the Naval Academy and got a master's degree at progressive St. John's College in Annapolis. Standing 6' 4", he is remembered as gregarious and embraced a Jesuit ideal by being a "Man For Others," friends and family said.

“He’s a person all those Jesuits wanted us to be,” said Ismay, a fellow Gonzaga graduate.

"The complexity of who he is, to me, is bigger than his being a SEAL. He was wickedly smart, but more on the creative side. He could play the trumpet, he could sing, he could write," recalled his first cousin, Jennifer Casey.

"Erik was funny as hell, always one of the boys," Marcus Luttrell wrote in his book "Lone Survivor.”

Ariann Harrison was an old friend in Washington who said he was sweetly absent-minded, once showing up for a swing dance class in flip-flops and yet "he made it work." They only discussed his SEAL career once -- when he told her he was going to Afghanistan.

"Before he left, I tried to convince him not to go," she said. "From a loyalty standpoint, he said he trained those guys and he was going."

The Wreckage

In July 2005, a few weeks after the crash of “Turbine 33,” the callsign of the MH-47E that Kristensen and 15 other SEALs and Task Force 160 “Nightstalker” special operations airmen perished aboard, a squad of paratroopers and Rangers descended the steep slope, charred black from burning jet fuel, with tree trunks sheared off from the exploding chopper.

A glimmer of metal caught a Ranger’s eye and he picked up a stainless steel dogtag bearing not a name but the Army’s Warrior Ethos: “I will always place the mission first. I will never accept defeat. I will never quit. I will never leave a fallen comrade.” The determination to not leave their fallen comrades was true of all 16 in Turbine 33 -- and was a promise fulfilled by their Jesuit-taught commander, Kristensen.

In unpublished photos taken by an Army photographer of the crash site, blackened tree stumps poke up from the flattened slope. Ammunition magazines for M4 rifles, springs and un-fired cartridges litter the sooted ground. Paratroopers held up a pair of Oakley mirrored sunglasses with one lens missing, a flight crew helmet torn open, a bent and flattened tactical flashlight and the lining of a SEAL's helmet they found on the ground.

The Taliban had pilfered the site, as well as the remains of Murphy -- they even stole his wristwatch -- and fellow SEAL operators Matthew Axelson and Danny Dietz in another location down the mountain in the forest. Later, militants would display captured U.S. weapons and laptop computers in a video. Night-vision goggles, weapons and helmets from both sites were recovered over the next two years from Taliban fighters killed in firefights and found in arms caches in the Korengal Valley. The militia leader, Ahmad Shah, was killed a few years later.

A photo of a Ranger’s gloved hand holding the dogtag imprinted with the Warrior Ethos sits framed in the Kristensen’s home, but until this month, his parents had never seen the rest of the crash site photos. Looking over the grim images for the first time, after an ABC News reporter provided them, Sam Kristensen said if conditions were ever safe enough and she had the opportunity to walk the ground where her son and his fellow warriors perished, "I'd be on the next plane -- a mother wants to know everything."

"I would've hated it if anyone had been killed on that recovery mission," she said after viewing the grim scene the young paratroopers had to sift through in July 2005. But seeing the site, even so long after, was helpful. "It will always be 'yesterday.' Ten years doesn't make any difference."

To cope with the catastrophic loss, she long ago befriended other moms who lost children inside the Pentagon on 9/11 and in Operation Red Wings, and a few years ago began volunteering to be an "Arlington Lady," a liaison to families of the fallen during Navy funerals at Arlington National Cemetery near their home on Capitol Hill.

"It is very redeeming thing. You are giving solace to someone other than yourself, and yet you are helping yourself," she said.

Ed Kristensen, quiet and soft-spoken, said he doesn't need to see that mountainside in Afghanistan to ease his grief, because he knows that Erik "was doing what he wanted to do. He could say that. That's how I remember him."

But they have grown weary of the past decade's seemingly endless tributes and memorial services for those lost in Operation Red Wings and the brutally violent "Lone Survivor" movie, which they watched three times at special screenings for families of the fallen. They participate in a golf tournament in Erik's name that helps military kids attend Gonzaga but the annual event they truly enjoy is "E-Day," a simple bar-b-que in Maryland hosted by Jennifer Casey and her siblings that brings together Erik's friends, family, Naval Academy classmates and SEAL teammates.

"Next year, I'm giving him up," Sam Kristensen said, half joking, of future tributes for her son. They only attended one memorial dinner in San Diego last week to mark the tenth anniversary of the Red Wings tragedy and turned down other invites to ceremonies. "It gets tiring. Physically, emotionally. We've hated to say no because people are very kind,” Sam said.

Remembrance in the Rain

As torrential rains in Maryland saturated a softball field and playground on Saturday, the friends of Erik retreated into an open air pavilion, where drenched children darted in the mud between adults laughing over "that one time" Erik had done this or joked about that, while the admiral donned an apron and flipped burgers on a grill. Kristensen’s cousins led the Pledge of Allegiance and a former SEAL who served with the mourned guest of honor strummed a guitar in sing-alongs.

Jarret Roth, a Naval Academy buddy, said Kristensen was excited about joining his girlfriend in Paris in 2006 after his Afghanistan deployment for an Olmsted Foundation Scholarship to attend the Institute for Political Studies and was thinking beyond his time in the SEAL teams. Kristensen once told Roth, "I don't know about this whole SEAL thing. Running around in the woods is kind of cool once in awhile, camping is kind of cool once in awhile. I don't know if I want to do this the rest of my life."

"Erik was probably the furthest from what you would have thought of a Navy SEAL. He was a bit of a chucklehead. A down to earth, happy-go-lucky guy," Roth said. "He was a very a selfless guy."

Kristensen's mother said swapping stories over beers and burgers is probably how the man his friends call the "gentle giant" would've preferred his life be celebrated, since he thought funerals were ridiculous and didn't even fill out the forms for his burial preferences, which most troops do. His parents buried Kristensen -- wearing his beloved Birkenstocks -- at the Naval Academy in Annapolis, which his father had also graduated from three decades earlier.

"We're so over this. I find it all really strange, all the hero talk. He was such a total goofball," remembered his friend Ismay, who graduated the academy a few years later and whose older brother served as a SEAL with Kristensen.

Kristensen applied but wasn't selected for Basic Underwater Demolition/SEAL school out of the academy. He served as a surface warfare officer at sea before finally making it through BUD/S at 26, considered an "old man" and just under the wire of the SEALs' age cut-off.

"Because he entered the teams a little later than his peers, he was a strong and humble leader. He could relate to the most junior guy and to a general or admiral," Paro said. "He was just a wonderful person. He was well-read and intelligent, into music and literature. He was a non-conformist."

"But he wasn't a non-conformist just to be a non-conformist," Ismay explained. "Erik was just his own man. He really didn't give a damn."

Kristensen's example of leadership and valor has become legend among the midshipmen of the Naval Academy.

However unusual a personality he had, those who knew him agree that he fell in battle personifying the words stamped into that dogtag picked up by the paratrooper in the grime of Turbine 33's wreckage ten years ago. "I will never leave a fallen comrade,” it read. Erik Kristensen and the fallen of Turbine 33 did not.

His vibrant personality appeared to live on as a powerful presence as his friends convened for the ninth time since 2005 on Saturday, shouting to be heard over the din of the downpour and laughing louder than the rain.

Smiling as he looked over the crowd and placing his hand on the shoulder of a first-time E-Day guest, his father Ed said, "He's amongst us all, right here."