DOLAN SPRINGS (AP) - Federal investigators on Sunday were combing the site of a bus crash that killed seven Chinese tourists on a rural Arizona highway near Hoover Dam.
The six-member investigative team will take measurements and photographs of the site, evaluate the condition of the highway, and look for skid marks and other clues that could point to what caused the crash, National Transportation Safety Board spokesman Peter Knudson said.
"These markings can be very important in telling the story of what happened," Knudson said.
Seven Chinese tourists were killed in the Friday crash on a straight stretch of U.S. 93, about 70 miles southeast of Las Vegas. Six of the deaths were confirmed at the scene, while a seventh person died at University Medical Center in Las Vegas. Ten others were injured.
The tourists left Las Vegas early Friday for a trip to the Grand Canyon and were returning when the bus veered right and then left across the median, rolling at least once before resting across the southbound lanes of the highway.
After investigators visit the crash site, they'll head to Kingman later Sunday to evaluate the bus. That will include checking whether the wheels and brakes were in good working order and whether any mechanical malfunctions may have caused the accident, Knudson said.
He said the investigators also plan to interview the bus driver, a 48-year-old man in fair condition at a Las Vegas hospital, and surviving passengers.
The investigation will take 12 to 18 months to complete, with the bulk of the work being conducted at the NTSB's headquarters in Washington, D.C., Knudson said.
"The goal is to get at the exact cause of the collision," DPS spokesman Lt. James Warriner said. "Was it mechanical failure? Was it driver error? All that will come with looking at the vehicle and conducting interviews."
DPS said Sunday that investigators would have no further information on the crash that Warriner said occurred on a "nice, clear day," until today.
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.
All but one of the victims killed are believed to have been ejected from the bus. The dead were taken to the Clark County Medical Examiner's Office in Las Vegas to be identified.
According to DPS, the bus belonged to D.W. Tours out of San Gabriel, Calif., which didn't respond to an e-mail from The Associated Press seeking comment.
Five people remained hospitalized at University Medical Center on Sunday, including the driver.
A 41-year-old woman who remained at Kingman Regional Medical Center was upgraded from fair to good condition Sunday. Family and friends visited her Saturday and she was awaiting more family traveling from China to see her, hospital spokesman Ryan Kennedy said.
"She's definitely doing fine," he said. "She didn't talk to much about (the accident). It's just one of those things where she's just trying to get better, and I think she's recovering well."