The crash involving a Martz bus occurred after 11 p.m. Sunday along Interstate 380 in Clifton Township, near Scranton, Lackawanna County 911 Supervisor Michael Kelechowa said.
Kelechowa said there were multiple injuries, but the exact number and severity weren't known.
County Coroner Tim Rowland said the bus hit one of two cars that had apparently been involved in a minor collision and were stopped on the road during the storm. A 41-year-old man who authorities believe was standing outside the car was killed when the impact of the bus pushed the car into him, Rowland said.
"He happened to be standing in the wrong place at the wrong time," Rowland said.
The bus rolled onto its passenger side shortly after hitting the car.
Rowland said he would not release the man's name until after his family had been notified. An autopsy was scheduled for later Monday.
State police were investigating, but said they had no additional information.