A chartered bus taking skiers home to Arizona ran off a curvy road and rolled down an embankment in a crash that split open the vehicle's roof and threw some passengers 100 yards. Eight were killed and 20 others injured.

The Arrow Stage Lines bus was southbound on State Route 163 when it failed to negotiate a curve Sunday night, went off the road and rolled over several times down the 41-foot slope, said Trooper Cameron Roden of the Utah Highway Patrol.

Although the road was described as wet from light rain, weather was not the "main factor," Roden said. "The main thing we're looking at is the driver failed to negotiate the turn."

The highway is known as a challenge for drivers.

"It's just a narrow road. No shoulders, sharp curves," said Jim Hook, the fire chief in Bluff, who was among the first at the scene. "Truckers and buses know that. You don't go in there at night."

The scene of the crash was a mess of barbed wire, steel posts, luggage and ski equipment. The roof of the bus split open, tires were stripped off the vehicle and some people were pinned under the wreck, Hook said.

"The roof of the bus was on the ground," Hook said. "There were people scattered 100 yards from where the bus went off the road."

The driver suffered minor injuries, he said. The bus was returning to Phoenix after a ski trip to Telluride, Colo.

The bus, which was carrying 51 people, crashed about 10 miles north of Mexican Hat, in the Four Corners region where Utah meets Arizona, Colorado and New Mexico. Rescue crews from all four states were sent to help.

Hook said passengers were a mix of families, people in their 20s, and children ages 5 and 6. Two of the dead were students at Deer Valley High School in Glendale, Ariz., said district spokeswoman Diane Drumwright.

An Arrow Stage executive, Bruce Neuharth, was traveling to the crash site Monday from Omaha, Neb., headquarters. He said the company and its subsidiary, Corporate Transportation 'N Tours, were cooperating with authorities.

The bus was a "new motorcoach that was in perfect working order," Neuharth said in a statement.

Arrow has had seven bus crashes in the past two years, according to the Federal Motor Carrier Safety Administration database. Four of those accidents involved injuries. No other details were available from the online database.

Elsewhere, two people were killed Monday morning in a car that collided with a school bus near Bartow, Fla., the Polk County sheriff's office said. None of the 11 students on the bus or their driver were injured. Deputies said the car veered into the path of the bus.

In Mapleton, Maine, a school bus went out of control at a sharp turn, clipped a utility poll and landed on its side Monday morning, sending six school children and the bus driver to a hospital with non-life threatening injuries, police said.