Investigators say winter weather in Westmoreland and Washington counties may be to blame for two accidents Thursday morning.

The first crash happened about 6 a.m. on Interstate 70 in Rostraver Township. Officials said a UPS truck overturned between the North Belle Vernon and Belle Vernon exits. The driver wasn’t hurt.

The crash caused backups into Washington County, where several vehicles collided in Fallowfield Township, about five miles from the first crash.

Authorities said the crash happened in the eastbound lanes by the California Exit.

“As I was coming to a stop, someone knocked on my door. It was a kid I worked with. He told me he got nailed from behind. He got hit hard –- he was delirious,” Rich Kronawetter said.

Emergency crews had to pull three people from their cars. There’s no word on their condition or what caused the crash.