The youngest victim of Friday’s deadly tour bus crash south of Hoover Dam was the first to be released from University Medical Center, hospital officials said Sunday.
An unidentified 8-year-old male was discharged from UMC, where several injured Chinese tourists were taken after a fatal accident in Arizona, on U.S. Highway 93, about 27 miles south of the dam.
A team of investigators is working to piece together what happened in the moments leading up the crash, which killed seven people and injured 10 others.
The identities of the 17 people on the bus at the time of the crash have not been released.
The condition of the 48-year-old bus driver improved from serious to fair Sunday, UMC spokesman Rick Plummer said.
The male bus driver and three other victims — a 35-year-old woman and a 40-year-old woman, both in critical condition, and a 61-year-old man in fair condition — remained under care at UMC.
The 8-year-old boy was released to his parents, who were treated at Arizona’s Kingman Regional Medical Center. The couple traveled by cab to Las Vegas to be with their son.
Two other crash victims at Sunrise Hospital and Medical Center — a 57-year-old man and 18-year-old woman — were upgraded to fair condition Sunday.
A 41-year-old woman, whose condition improved from fair to good, remained at the Kingman hospital.
A six-member federal investigative team documented the crash site Sunday to determine the sequence of events leading up to the crash, National Transportation Safety Board spokesman Peter Knudson said.
Investigators also traveled to Kingman, where the tour bus was towed, to see whether mechanical issues contributed to the crash.
"The police may be interested in liability; our’s is just focus on safety," Knudson said. "We want to know what went wrong and to use that info to make safety recommendations."
The inquiry could take up to 18 months, Knudson said.
Arizona Department of Public Safety spokesmen said they probably will have some results of a search of the bus this week that might point to what caused the crash.
Tourists on the bus were Chinese nationals who had flown from Shanghai to San Francisco and most recently had been in Las Vegas, the Arizona Department of Public Safety said.
They left Las Vegas early Friday for a trip to the Grand Canyon. On the return trip, the bus veered right and then left across the median, rolling at least once before coming to rest across the southbound lanes of the highway.
Authorities said the bus belonged to D.W. Tours out of San Gabriel, Calif.
The Associated Press contributed to this report. Contact reporter Maggie Lillis at firstname.lastname@example.org or 702-383-0279.RELATED STORIES Jan. 30: At least 7 die, 9 injured when tour bus crashes on U.S. 93 in Arizona Jan. 31: Some injured bus crash tourists released from hospital Feb. 1 Some crash victims better