Investigators in southern California were trying to determine why a tour bus plowed into the back of a tractor-trailer truck on Interstate 10 early Sunday, killing 13, including the bus driver.
The crash injured 31, including the driver of the truck.
Among the deadliest bus crashes in California in recent years, Sunday’s pre-dawn crash took place about 100 miles east of Los Angeles as California Highway Patrol (CHP) officers slowed traffic to allow utility workers to string wires across Interstate 10.
CHP Border Division Chief Jim Abele said the cause of accident wasn’t clear and that investigators “may not determine how the accident occurred” because the bus driver was killed. But he said the bus was going significantly faster than the truck at the time of the crash.
The truck driver survived with minor injuries.
National Transportation Safety Board (NTSB) investigators on Sunday were expected to examine the crash scene.
Abele said the bus plowed 15 feet into the back of the truck in a “substantial impact.” He said it was unclear why the bus was traveling at a much faster speed than the truck. It was also unclear whether drugs or alcohol were involved, or whether fatigue was a factor. The crash took place shortly after 5 a.m. local time.
“Right now we’re looking at everything,” Abele said.
All westbound lanes of I-10 were closed following the crash. Stuck in the traffic were Chris and Rachel Williams, who were about five vehicles east of the scene and waited more than an hour.