The coach of the Penn State Lehigh Valley boys basketball team had just dozed off as the team bus cruised along Interstate 78 en route to a game in western Pennsylvania.

Outside, the heavy snow turned into a whiteout. And mayhem ensued on this busy stretch of rural Lebanon County highway.

Over the next 10 minutes early on Feb. 13, 2016, 64 vehicles would crash, killing three people and injuring 73.

"I remember us hitting - we hit the rear of somebody pretty hard,'' said coach Michael DeCarolis. "The bus driver began screaming, 'Everybody get in the front of the bus - we're going to get rear-ended.'"

After the bus was hit, it became eerily quiet, DeCarolis said.

"When the squall died down, you saw carnage all over the place,'' he said. "You could see people lying on the [road]."

Thirteen players sustained only minor injuries, such as bumps and bruises and minor cuts. A few got out and tried to help people.

As DeCarolis was assessing the injuries to his team, emergency crews started to respond. For many, this would be the single-worst incident of their careers.

"My initial impression was it was just overwhelming," said Robert Taylor, chief of Jonestown Perseverance Fire Company, who was in charge of fire command at the scene. "Most difficult was the sheer volume of people," Taylor said.

And the scope of the crash was so big the state police reconstruction report is still being analyzed, said Trooper David Beohm, spokesman for state police Troop L. No charges have been filed.

Traveling in the opposite direction of the Penn State bus, Camp Hill High School track coach Mike Barndt was taking two of his runners to Lehigh University for a meet when they came up to the massive crash in Bethel Township, about 7.5 miles east of where Interstates 81 and 78 split.

"We were the second stopped vehicle going east," he said, due to the emergency response to the pileup.

As they approached Fort Indiantown Gap, Barndt said, "All of a sudden the road went from a sunny morning to a snow squall. Literally the road went from bare to over an inch to two inches of snow in less than half a mile."

Barndt, a former truck driver who has a commercial driver's license, said he gave space to the tractor-trailer in front of him and pumped his brakes.

"Thank God behind me was the same kind of driver in the big rig behind us," he said, although that driver ended up about 10 feet from his van.

Two more squalls came through while they were stopped, Barndt said.

"It was really rocking and rolling - 35 mph or more. You could see it coming down the 81 corridor across 78," he said.

In addition to the squall in near-zero wind chills, 20 to 30 mph wind gusts were also blowing off neighboring fields.

John Wilson, Lebanon County's emergency management director at the time of the crash, said drivers reported coming "into a wall of snow and they didn't know what was on the other side of it."

Drivers reported the road "turned to instant ice," Beohm said.

"Drivers all kind of said the same thing with regard to whiteout conditions - visibility was reduced to about 100 feet, it got snowy really quick ... conditions were blizzard-like," Beohm said.

Once the crashes began, drivers were faced with making split-second decisions.

"Some people tried to get away and drove into the median, while some other people didn't even know it was happening and said they just hit stuff - other vehicles," Beohm said.

How the pileup unfolded

Sixty-four vehicles collided - 51 non-commercial vehicles and 13 commercial, including a dozen tractor-trailers and a bus, state police say.

Before the big pileup, there was a minor collision between a tractor-trailer and a Ford Focus at mile marker 7.4, one-tenth of a mile west of the bigger crash, possibly because of the white-out, Beohm said. These two vehicles were on the berm. There was also another tractor-trailer in the median, possibly also because of the squalls.

The first vehicle in what became the major pileup at mile marker 7.5 was a tractor-trailer, which hit the back of a Fed-Ex double tractor-trailer, which was slowing or had stopped due to the whiteout or the earlier crash or the rig in the median, Beohm said.

The driver of the first tractor-trailer, Alfred Kinnick, 57, of Limestone, Tennessee, was thrown from his cab and died of injuries at the scene. His truck was also struck in the rear by another tractor-trailer.

The first crashes were in the travel lanes, then vehicles ran onto the median and berm trying to avoid them and find a place to stop in the squall. Some pulled over safely, but were then hit by others.

"Every car in there probably was hit at least once or twice," Beohm said, with one hit five times.

"Once it started, it just continued," Beohm said. "You were just like a pinball going up through there," one driver told police.

A second fatality was Francisca Pear, 54, of Bridgewater, New Jersey, the driver of a brown Toyota Tacoma pickup truck.

The pickup came to a stop on the berm and was hit by a Peterbilt tractor-trailer with a black cab, a van and a Ford F-150 pickup truck. The Tacoma came to rest partially on top of the guardrail on the berm, Beohm said.

The third fatality was Kenneth Lesko, 50, of Bethpage, New York, who was driving a black Dodge Ram pickup truck. He came to a stop and was struck by a tractor-trailer that pushed the pickup into the side of another big rig, which rolled over. Yet another big rig then hit the rear of the Dodge Ram, causing the pickup to roll over and trapping it under the front end of the rig.

How was the response?

"The real stars last year were the Lebanon County emergency responders. They had a real strong response, people working together out there," said Greg Penny, PennDOT District 8 spokesman.

"The cooperation between all the agencies involved is what enabled this incident to go as smoothly as it did," said Bob Dowd, Lebanon County EMA director since December.

Still, the pileup was daunting.

"My first reaction was it was difficult to comprehend the scope of what had happened," Dowd said. "There was no one spot where you could see the entire scene," he said, adding it was the worst single incident in his 15-year career.

"It was probably the worst incident in terms of injuries," added Wilson, the EMA director at the time of the pileup.

Robert Taylor, chief of Jonestown Perseverance Fire Company, who was in charge of fire command at the scene, said, "My initial impression was it was just overwhelming."

"Most difficult was the sheer volume of people," Taylor added, and getting them triaged, extricated and to hospital or a warm site. Still, he said, patients were out of the wreckage and transported in a timely manner.

Both sides of the interstate were closed down about 9:45 a.m. By 11 a.m., EMA had established unified command in a trailer brought to the scene, where fire, emergency medical services, police and EMA response was coordinated. At the county operation center, the Pennsylvania Emergency Management Agency assisted the county EMA.

By then, all of the ambulatory patients were already in the back of a trailer and rescue operations were either completed or under way.

The incident stressed EMS resources such as ambulances, Dowd said. The injured were sent to 10 or 11 hospitals.

Bryan Smith, executive director of First Aid & Safety Patrol, said prior training prepared them for this disaster.

As they triaged the injured and tagged vehicles, Smith said, it was tough to tell those with less serious injuries they'd be back later to help them.

"[Responders] literally crawled over vehicles with people in them to get to people worse off in other vehicles," Taylor said.

Difficulties included radio batteries dying in the cold and some aspects of communications.

Dowd said they're in the process of adding new radio protocols to improve on communication.

"They were not problems that hindered patient care," he said. "In public safety, we learn from every call."

"We had a lot of stuff that went our way, for sure," Taylor said, including the location of the crash. Instead of being in a more isolated location, like the Pennsylvania Turnpike pileup near Somerset in mid-January 2016, this incident was at a spot where they could get on and off I-78 within a mile or two.

There were no hazardous materials or large fires, Dowd said.

It also helped that the incident occurred on a Saturday rather than during the work week, when emergency responders were available.

What should you do in a crash like this?

"If it's a total whiteout, you'd be the safest in your car, which is built to crumple around you. If you run across the road and here comes a car sliding out of control, you have no protection," Beohm said.

If come upon an accident or whiteout in wintry weather, put your four-way flashers on and slow down.

"Be as alert as you can be, especially in winter weather," he said. A darkening of the sky ahead of you in daylight could be a squall.

PennDOT was able to respond quickly because skeleton crews were called out the day before, based on a forecast of possible snow showers and squalls for Feb. 13.

Dave Rock, District 8 assistant district executive for maintenance, said that with the Great American Outdoor Show going on at the Farm Show in Harrisburg, he decided to have a few crews out in each section of the district that morning.

Once the accident occurred, "it was all hands on deck," Rock said. PennDOT crews worked with state police and emergency responders to close roads and set up detours.

This was the only spot with squalls that crews encountered, Rock said.

"That was definitely the worst crash in my area," Rock said. "Three people lost their lives. There was just a lot of sadness that day."