REDWOOD CITY (CBS SF) — An early morning crash between two vehicles on U.S. Highway 101 in Redwood City turned fatal when a third vehicle slammed into the crash scene, the California Highway Patrol reported.

The crash happened just before 4 a.m. on northbound 101 between Marsh Rd. and Woodside Rd. The CHP said there was a collision between a red pickup and a white mini van that left the pickup in the center lanes facing the wrong way.

READ MORE: UPDATE: Fire Destroys 2 Pleasant Hill Homes; Resident Still Missing, Firefighter Suffers Burns

A third vehicle, another white van, then collided head on with the pickup truck in the center lanes. The driver of the pickup was killed in the head-on collision, the CHP said.

READ MORE: Drought: Transbay Pipeline, Desalination Plant Could Boost Marin's Dwindling Water Supply

There was no immediate word on what caused the crash or if speed, drugs or alcohol played a factor.

MORE NEWS: U.S. Supreme Court Sides With College Athletes In Key Compensation Case

Traffic was severely backed up for hours after the crash as investigators processed the scene and all lanes except the far left lane was closed.