The Chinese tourists left Las Vegas early Friday for a trip to the Grand Canyon and were returning Friday afternoon when the crash occurred on a straight stretch of U.S. 93, about 70 miles southeast of Las Vegas, authorities said. Six fatalities were confirmed on the scene. A seventh person died at University Medical Center in Las Vegas, and 10 others were injured, said Arizona Department of Public Safety Cmdr. Dean Nyhart.
"The goal is to get at to the exact cause of the collision," said DPS spokesman Lt. James Warriner. "Was it mechanical failure? Was it driver error? All that will come with looking at the vehicle and conducting interviews."
A six-member team from the National Transportation Safety Board was scheduled to be on scene Saturday to assist with the investigation, said NTSB spokesman Peter Knudson. DPS also had investigators at the site.
Authorities said the tour bus, which was taken to a state Department of Transportation yard in Kingman, veered right and then left across the median, rolling at least once before resting across the southbound lanes of U.S. 93.
Police did not describe the road and weather conditions at the time of the crash.
Tourists on the bus were Chinese nationals who had flown from Shanghai to San Francisco and had most recently been in Las Vegas, according to DPS.
Nyhart said he believes all but one of the victims killed at the scene were ejected from the bus.
The dead were taken to the Clark County Medical Examiners Office in Las Vegas to be identified.
According to DPS, the bus belonged to D.W. Tours out of San Gabriel, Calif. A recorded message on the company's phone line said the mailbox was full and that no messages could be left. The company didn't respond to an e-mail from The Associated Press seeking comment.