Lanes of the northbound San Gabriel River (605) Freeway were shut down Sunday after a vehicle went off the side at Rivergrade Road, authorities said.
The crash was reported at 3:58 a.m. and witnesses told the California Highway Patrol one occupant of the vehicle was unconscious on the right shoulder while another was trapped in the vehicle and a third person was also in the area.
Paramedics took one person to a hospital for treatment, Los Angeles County Fire Department Dispatch Supervisor Martin Rangel said.
The northbound 605 in the area was shut down so debris could be removed from lanes and Caltrans was called to repair about 50 feet of damaged guardrail, the CHP said.