Three Chinese tourists remained in critical condition Monday after they were injured in a tour bus crash in southern Utah that left four other passengers dead, hospital officials said.
One person was in serious condition, but other passengers hurt in the crash were improving.
The tour bus carrying 30 people rolled over and crashed Friday onto a guard rail on its way to Bryce Canyon National Park. Everyone on board was hurt.
The cause of the crash hasn't been determined by U.S. investigators. Regulators said the driver — a U.S. citizen from California whose name has not been released — was making his first trip.
He didn't appear to be intoxicated, the Utah Highway Patrol has said.
U-Tour Group in Shanghai, the travel company overseeing the U.S. trip, said the driver was qualified, the bus was insured, and the travel agency was properly registered with China's Ministry of Culture and Tourism.
The operator of the bus, Ontario, California-based America Shengjia Inc. was cooperating with investigators examining what caused the mid-sized 2017 bus to crash, authorities said.
The company has not responded to requests for comment.
The bus had seat belts, but it's unknown if any passengers were wearing them.
Utah officials don't require state permits from out-of-state tour bus companies or track who's coming through the state as long as the carrier is registered with the U.S. government and their home state, said Chad Sheppick, Utah Department of Transportation's director of the motor carrier division.
In this case, documents available online show America Shengjia had done both.
Three women and one man died in the crash. The victims have been identified as Ling Geng, 68, Xiuyun Chen, 67, Zhang Caiyu, 62, and Zhongliang Qiu, 65, according to the Utah Highway Patrol.
The group of 29 tourists and one leader came from Shanghai and the provinces of Zhejiang, Jiangsu and Heilongjiang, according to a news report on the media website huanqiu.com.
McDonald reported from Beijing. Associated Press writer Brady McCombs in Salt Lake City contributed to this story.