The crash was reported just after 3:30 a.m. on the northbound 5 Freeway at Terra Bella Street. The incident involved a white Honda sedan, according to the California Highway Patrol traffic log.
The Los Angeles Fire Department said firefighters and paramedics responded to the scene and pronounced one person dead.
The CHP issued a SigAlert at 3:53 p.m., closing all northbound lanes, except for the carpool/HOV lane, during the investigation.
The SigAlert was canceled shortly before 8 a.m. and the freeway was fully reopened.
The cause of the crash is under investigation. No further details were immediately known.