A commuter train and a truck have collided, causing three carriages to derail northwest of Los Angeles.
The vehicle became engulfed in flames and at least 28 people have been injured, a fire department spokesman told the BBC.
Police in Oxnard, California, say the crash was first reported at 05:44 local time (13:44 GMT).
A helicopter from a local television station is showing emergency responders treating multiple people.
A spokesman for the Ventura County Fire Department told the BBC that it is believed no one had died in the accident