"(Investigators) feel it was going to be driver error," UHP trooper Cameron Roden said Friday. "He was not paying attention and went off the shoulder of the road and lost control."
The driver was cited for failure to operate within a single lane, the UHP said.
The crash happened about noon Thursday on state Route 12 in Red Canyon. Troopers said the bus left the roadway and tumbled down an embankment, landing on its top and catching fire. Everyone managed to escape the blaze.
The bus was ferrying 47 teenagers and six counselors as part of a tour group going from Zion National Park to Bryce Canyon National Park. They were all from the east coast, authorities said. The tour bus, part of the Rein Teen Tours, was based out of New Jersey, authorities said.
Garfield County Sheriff's spokeswoman Becki Bronson said some of the teens were knocked unconscious in the crash, but none of their injuries were life-threatening.
"Some of the injured are reported to be wearing neck braces, back braces or bandages, but no broken bones or puncture wounds were reported to the sheriff's office," she said in an e-mail.
E-mail: bwinslow@desnews.com