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

It’s still early in the investigation, but officers have found evidence of tread separation on the left front tire of the full-sized bus, Trooper Kevin Honea said.

Three people remained in critical condition Monday at University Medical Center in Las Vegas, including the driver, said spokeswoman Tammy McMahan.

Herbst Gaming Inc. president Ferenc Szony said there were 33 employees on the chartered bus when it crashed Sunday night on Interstate 15 about eight miles south of the Las Vegas Strip. The bus was shuttling the workers to Las Vegas from the state-line town of Primm.

Wheels and suspension components were ripped from the bus and strewn across the highway, he said.

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. Inspectors also looking at the vehicle’s mechanical systems.

(This version CORRECTS that the wreck was Sunday, not Saturday.)