Investigators confer at the scene of a mass casualty bus crash on the westbound Interstate 10 freeway near Palm Springs, California October 23, 2016. [Photo/Agencies]

The injured were being treated at hospitals while all westbound lanes of the interstate were closed near the crash, officials said. Abele said the lanes would likely be reopened around 4 pm.

Abele said the bus appeared to be ferrying casino-goers back to Los Angeles from the Red Earth Casino after a night of gambling.

The Los Angeles-area bus company, USA Holiday Bus, could not immediately be reached for comment. The local Desert Sun newspaper reported the driver was one of the company's owners.

Abele said USA Holiday appeared to be an "owner-operator" company and that the totaled bus was the only one owned.

The National Transportation Safety Board said it will investigate the crash and is sending an investigative team to the site.

Abele said it was not immediately clear if alcohol, drugs or fatigue was a factor in the crash. He said it was not clear whether the bus was speeding, but said it was traveling "significantly faster" than the tractor-trailer.