DISCOVERY BAY (CBS SF) — A 17-year-old motorcyclist was killed Monday in a crash with a big rig along state Highway 4 in Discovery Bay, authorities announced.

The California Highway Patrol said the crash happened at about 1:45 p.m just west of the Discovery Bay Bridge. Contra Costa CHP said the 17-year-old had just passed another vehicle when he collided with the big rig.

The teen motorcyclist from Stockton was pronounced dead at the scene, while the driver of the truck was not injured. The coroner’s office had not yet released the teenager’s identity as of Monday afternoon.

The CHP said alcohol and/or drugs do not appear to be a factor in the crash, but it was still under investigation.

Anyone who witnessed the crash or any events leading up to the crash was asked to contact Contra Costa CHP at (925)646-4980.