Four people, including two small children, were killed Saturday in a pileup on Interstate 15 in Ontario.
California Highway Patrol officer Jeff Briggs told the Associated Press the four dead were in a car that was sandwiched between two tractor-trailers and caught fire on the southbound freeway.
Three other people were injured, he said.
The freeway was shut down for several hours for the investigation.
There was no word on what caused the crash, but Briggs said victims were killed at the end of a long chain-reaction of crashes. They were all declared dead at the scene.