Los Angeles County Fire Department crews airlifted four people after their vehicle rolled down an embankment in the Angeles National Forest.
Each was taken to a nearby hospital for treatment -- three by helicopter and one by ambulance.
CBS Los Angeles reported that the incident was first reported just after 11 a.m. Thursday on the Angeles Crest Highway, near mile marker 27-50, when the vehicle reportedly drove through the guardrail lining the road and rolled over 300 feet to the bottom of the embankment.
California Highway Patrol investigators detailed that there was no indication that the car was speeding before the crash, though witnesses at the scene described a different series of events.
Kate Campos, who said she witnessed the whole thing, told CBS that "I guess it was racing. They were trying to pass another car that was in front of it and they went to the left ... that's when they started rolling down."
The cause of the crash is under investigation.
