The crash shut down westbound lanes shortly before 5 p.m. and prompted a response from the California Highway Patrol and the L.A. Fire Department.
Authorities said two people in the vehicle died after they slammed into the rear of the truck. The driver of the truck was uninjured.
Footage of the crash showed the front-end of the vehicle underneath the trailer near the La Tuna Canyon Road exit.
CHP later reopened some lanes.
Further details about the collision were unavailable.