The incident happened around 2 a.m. Friday on the 1300 block of Paseo del Mar. Responding officers said they could hear someone calling for help, so rescue crews from the fire department were called to the scene.
The 19-year-old male victim was pulled from the car and airlifed to a hospital in Torrance with serious injuries.
The driver's statements to investigators, as well as physical evidence at the scene, indicated that he intentionally drove off the cliff's edge in what may have been a suicide attempt.
Authorities planned to retrieve the vehicle from the bottom of the cliff during daylight hours by using heavy-duty tow equipment.