A Las Vegas-based tour bus heading to the Grand Canyon rolled over in northwestern Arizona on Friday, killing one person and critically injuring two others, authorities said.

A spokeswoman for the Mohave County Sheriff's Office said the cause of the Friday afternoon wreck was not yet known, but a fire official who responded said speed appeared to be a factor.

He slid down the road quite a ways, so there was a lot of wreckage," said Lake Mohave Ranchos Fire District Chief Tim Bonney.

"A lot of them were saying the bus driver was driving at a high rate of speed," he said.

A photo from the sheriff's office showed the bus on its side on a road that curves through Joshua trees with no snow or rain in the remote area.

This photo provided by the Mohave County Sheriff's Office shows a Las Vegas-based tour that rolled over in northwestern Arizona on Friday, Jan.

(Mohave County Sheriff's Office via AP).

There were 48 people on the bus, including the driver, authorities said.

Two people were critically injured, said Mohave County sheriff's spokeswoman Anita Mortensen.

The bus was heading to Grand Canyon West, about 2 1/2 hours from Las Vegas and outside the boundaries of Grand Canyon National Park.

Before the pandemic, about 1 million people a year visited Grand Canyon West, mostly through tours booked out of Las Vegas.