TEMECULA (CBS 8) - The investigation continues into a tour bus crash near Temecula. Ten of the 18 people onboard were injured in the crash.

According to authorities, the bus was on its way from Los Angeles to Casino Pauma just before 11:00 p.m. Sunday, when the brakes failed on Pala-Temecula Road. The bus hit a metal guardrail, then collided with several trees before stopping off the right shoulder.

"Coming down this road a little bit further down, there's a lot of twists and turns and cliffs, so this could have been a lot worse than it actually was," explained Jim Bettencourt with the California Highway Patrol.

All of the passengers were from the Los Angeles area. Ten people, including the driver, were taken to Palomar Medical Center. Authorities say most had suffered cuts and bruises and were complaining of pain.

Bettencourt said it does not appear that alcohol or drugs were a factor in the collision. The roadway was closed for several hours. The bus is being kept as evidence by police.

The collision is under investigation.