At least nine people have been killed and up to 30 critically injured after two commuter trains collided near downtown Los Angeles early this morning.
Emergency teams are picking through the debris of the crash, which also involved a parked freight train, and can be seen carrying some victims away on stretchers.
One of the train cars caught fire and another rolled to its side in the crash, which occurred at about 6 a.m. local time (2 p.m. Irish time).
Authorities are unsure if some passengers are still trapped inside the toppled train.
The cause of the accident is still unclear, said a spokeswoman for Metrolink, which operates the commuter rail lines.
A spokesman for Union Pacific said its train was parked on another track when it was struck after the initial accident.
About 70 passengers with minor injuries including facial cuts and bruises were ushered into an improvised treatment center outside a Costco store near the tracks, in an industrial area near the Atwater Village neighborhood of Los Angeles.
One of the commuter trains, which had departed Union Station in downtown Los Angeles, was mostly full, witnesses said.