CINCINNATI -- A Greyhound bus drove off an interstate highway in southwest Ohio early Saturday, struck a tree and a fence and flipped on its side before sliding to a stop in a cornfield, injuring at least 35 people.
None of the injuries was considered life-threatening, though several people were trapped and had to be extricated by firefighters and paramedics, the State Highway Patrol said.
Patrol Sgt. Pete Combs said an investigation was under way and he couldn't comment on a possible cause of the crash, which happened about 4 a.m. on Interstate 75 in Liberty Township, about 25 miles north of Cincinnati.
But passenger Christopher Link, of Michigan, told WCPO-TV in Cincinnati that he saw the driver slumped over. Link said he heard a woman scream at the driver "Wake up! Wake up!" but that he thinks the man might have had a medical problem.
Link told the station the bus rolled over at least twice after hitting the tree.
Jeff Galloway, director of the Butler County Emergency Management Agency, said 35 people were taken to hospitals, six by helicopters and 29 by ambulance. The injuries ranged from minor to severe, officials said.
The bus, which left Cincinnati bound for Detroit, was carrying 51 passengers and the driver. Those passengers who were not injured and those who were treated and released from hospitals were transported back to Cincinnati, but none of them were at the bus station later Saturday morning.
At least nine people remained in hospitals Saturday night.
The driver, who has been with the company for almost 15 years, had been on duty for an hour and was fully rested, Kim Plaskett, a spokeswoman for Dallas-based Greyhound Lines Inc., told the Associated Press.
The driver was among the injured, but she said she could not release the person's name or medical condition due to medical privacy laws.
Plaskett said she couldn't discuss any details of the crash or the possible cause. The company was cooperating with investigators and will talk to the driver and conduct an internal investigation to try to determine what happened, Plaskett said.