A pileup involving dozens of vehicles on a Pennsylvania interstate that killed three people and sent scores to hospitals appears to have been related to a passing snow squall, authorities said Saturday.

Trooper Justin Summa said three fatalities had been confirmed and an unknown number of critically injured patients were flown to hospitals. Seventy more were transported by ambulance to other facilities following the crash in Interstate 78 in Fredericksburg.

State police said more than 50 vehicles were involved in the crash, which happened around 9:45 a.m. The pileup left tractor-trailers, box trucks and cars tangled together across three traffic lanes and into the snow-covered median about 75 miles northwest of Philadelphia.

Megan Manlove of Penn State Hershey Medical Center said 10 patients had been brought in from the crash, three in critical condition, three with moderate to severe injuries and four with minor injuries.

Trooper Adam Reed said investigators believe that "passing snow squalls played a role in causing the crash."

PennLive.com reported that some witnesses reported sudden whiteout conditions on the interstate before the crash.

"It just turned real white," Raul Jardine of Allentown said, adding that all he could see were the brake lights of the car in front of him, so he slowed down and was hit from behind.

Summa said several buses of stranded passengers were taken to a warming shelter at a firehouse in the area.

"We're keeping them warm, keeping them fed and hopefully going to provide them with some rental cars," he said.

The Penn State-Lehigh Valley men's basketball team was heading to a game in New Kensington when the team's chartered bus was hit by a tractor-trailer, the university said. Officials said there were no serious injuries to anyone and the students were "on a warm, dry bus" but were being taken to a hospital as a precaution.

Pennsylvania Emergency Management Agency spokesman Cory Angell said an emergency operation center was activated and a special response team was at Fort Indiantown Gap to deliver stockpiled supplies such as food and water if they are needed.

Angell said drivers were being urged to use caution due to extremely cold temperatures and blowing snow making roads hazardous even though they have been plowed.

"You could be driving down the interstate and all of a sudden conditions change because the winds are drifting the snow," he said.