Greyhound bus crash injures dozens

An injured passenger is wheeled away at the scene of a bus accident on Sunday in Casa Grande, Arizona.

PHOENIX, Arizona (CNN) -- A passenger tried to grab the wheel of a Greyhound bus Sunday, causing the vehicle to turn on its side and injuring more than 30 people, the Arizona Department of Public Safety reported.

The bus, carrying 38 people, was southbound on Interstate10 at Casa Grande, about 40 miles south of Phoenix, when the man approached the driver about 1:06 a.m. (3:06 a.m. EST) , said Officer Hyrum D'Addabbo.

During the scuffle, the bus drove off the pavement, then back onto the roadway before turning on its side, blocking traffic, he said.

Thirty three-people were taken to hospitals, none with life-threatening injuries, DPS spokesman Steve Volden said. He said the driver wasn't hurt, and no weapon was involved.

Volden said the passenger was charged with 37 counts of aggravated assault. No motive was known for the attack, he said.

Lynn Brown, Greyhound's vice president of corporate communications, said the bus was en route from Phoenix to El Paso, Texas. It was an "isolated incident involving an unruly passenger," Brown said.

In October, a man on a Greyhound bus tried to take control from the driver and, when he failed, escaped in a separate vehicle. The incident occurred east of Salt Lake City, Utah.

Also in October, six people died and 32 were injured when a man slit the throat of a Greyhound bus driver in Tennessee and the bus flipped on its side.