Greyhound bus overturns in Nevada

The bus, scheduled to arrive in Los Angeles, overturned in Nevada early Tuesday morning

GLENDALE, Nevada (CNN) -- A Greyhound bus overturned in Nevada on Tuesday, injuring many of the 43 passengers on board.

At least 29 of the 43 passengers were sent to area hospitals, Greyhound spokeswoman Kristen Parsley said.

Two people -- including the driver -- sustained life-threatening injuries and were taken to the University Medical Center in Las Vegas -- about 55 miles away.

Trooper Alan Davidson, a spokesman for the Nevada Highway Patrol, said no fatalities have been reported.

The accident happened around 3:20 a.m. (6:20 a.m. EDT). The bus -- which originated in New York -- was scheduled to arrive in Los Angeles at 10:30 a.m. (1:30 p.m. EDT) on a regular Greyhound route, Parsley said.

Skid marks on the scene of the accident indicated the bus -- entering Interstate 15 from an on-ramp -- was traveling too fast, Davidson said. The driver couldn't negotiate the turn onto the highway and the bus flipped down an embankment, he added.

"It is apparent that it is driver error at this point," he said, adding that the cause of the accident is still under investigation.

Davidson described the scene as "traumatic," saying that ambulances were lined up for a quarter-mile to treat the injured.