CIRCLE, Mont. — A bus driver was among the individuals killed in an accident last Wednesday involving a school bus and a Ford Explorer Sport Trac SUV.

Montana Highway Patrol Trooper Nyle Obergfell told the Billings Gazette that the SUV was traveling eastbound on a highway and the school bus was in the westbound lane.

“It looks like the Explorer for some reason drifted over into the westbound lane and collided head-on with the bus,” Obergfell said.

Both vehicles caught fire. The school bus driver, who worked for Circle School District 1, was killed, along with the male driver and female passenger of the SUV. There were no children on board the bus.

Don Whitmus came across the crash while driving toward Billings, Mont. Whitmus tried to get inside the bus, but the flames were too intense, the Billings Gazette reports. A nearby resident then arrived and tried to get to the bus driver out of the vehicle through its rear emergency exit, Whitmus told the newspaper, but the heavy smoke drove him back.