LAS VEGAS — Tire failure may have caused a casino worker shuttle bus crash that injured 29 people, a Nevada Highway Patrol officer said Monday.

"There's evidence that the bus may have suffered tire tread separation," Trooper Kevin Honea told The Associated Press. He said the findings were still preliminary.

Federal officials also have reported evidence of tread separation in the crash in Texas of a bus chartered by a church group. That wreck early Friday killed at least 17 people.

Those injured in the Nevada crash Sunday on I-15 were casino and mall employees returning to Las Vegas from Herbst Gaming Inc. properties in nearby Primm, said Ferenc Szony, company president.

Clark County fire spokesman Scott Allison said the crash scene stunned him.

"The driver's side front tire looked like it went through a meat grinder," Allison said. "It was just shredded completely."

Honea said witnesses saw the bus veer suddenly to the left, where a guardrail sheared off its wheels and undercarriage. The coach section crashed into the center median and remained upright. He said the bus did not appear to have been speeding.

Three people remained hospitalized Monday at University Medical Center in Las Vegas, said hospital spokeswoman Tammy McMahan. She said patient privacy laws prevented her from disclosing medical conditions.

Honea said the bus driver was among those still hospitalized.

Bus owner AWG Charter Services of Las Vegas released a statement saying more information would be made available when the investigation is completed, but it referred questions to an insurance adjuster.

The adjuster, Duane Ford, said the driver was not fatigued and the bus was well-maintained.

"The wheel and the remnants of the tire are still intact on the bus, so it looks like something deteriorated in the tire," Ford said.

It was the second crash this year involving Herbst casino workers being shuttled 40 miles between Las Vegas and Primm, a freeway casino town on the Nevada-California state line. A Jan. 17 wreck injured at least 25 people, but everyone got out before the bus was destroyed by fire. That bus was owned by Herbst Gaming, not AWG.

A casino bus also was involved in an accident Sunday in Mississippi that killed three people and injured more than 30.

The bus belonging to Harrah's Tunica was carrying 43 people when it overturned at an intersection in Tunica, authorities said. Rain was falling at the time but Mississippi Highway Patrol Sgt. Leslie White would not speculate on the cause of the wreck.

In Texas, 17 people have died as a result of a wreck on Friday that involved a chartered bus. Authorities said that vehicle's right front tire blew out and had been retreaded in violation of safety standards that prohibit such work on steering axles. Inspectors also looking at the vehicle's mechanical systems.