PHOENIX (AP) -- The Arizona Department of Public Safety says a tour bus overturned on a highway near the Hoover Dam, killing at least seven passengers and injuring at least 15.
A DPS news release says the crash occurred about 4 p.m. Friday in northwestern Arizona.
Six fatalities were confirmed on the scene, about 190 miles northwest of Phoenix; a seventh person died at a Las Vegas hospital, said Cmdr. Dean Nyhart with the Arizona Department of Public Safety.
Nyhart said the bus was traveling north on U.S. 93 when it veered left and then right across the median. It rolled at least once before stopping.
He believes all but one of the victims killed at the scene had been ejected from the bus.
Nyhart said five people had suffered life-threatening injuries. "We're hopeful that those people can be stabilized and at least the death toll stop where it is," he said.
The driver of the bus was among those in critical condition, he said.
Nyhart said the tourists on the bus were Chinese nationals who had flown from Shanghai to San Francisco. Investigators were still searching for the bus manifest for more details on its route.
He said investigators were struggling to identify the injured and were not certain how many passengers were on the bus or how many had been transported to hospitals.
"We're hearing anywhere from 15 to 20. So we're not even sure how many people were on board," he said. "We have passports, but it's going to be very difficult to ID the dead because those that are still alive are in critical condition. Many of the passports were left in the luggage as people were transported."
The crash closed down U.S. 93 in both directions. The highway is the main route between Phoenix and Las Vegas.