The two-vehicle collision was reported just after 5 a.m. at the 170 Freeway interchange, the California Highway Patrol said.
[Ads /]
A fire erupted when the big rig collided with a white van that was stalled in lanes, according to a CHP incident log. Firefighters arrived at the scene and extinguished the flames.
It was unclear whether the deceased were occupants of the semitruck or the van. They were were not immediately identified.
[Ads /]
Traffic on the southbound 5 Freeway was backed up for miles as crews worked to clear the charred wreckage of the van from the scene. Morning commuters were being diverted onto the southbound 170 Freeway.
A SigAlert was canceled shortly before 11 a.m. and all lanes were reopened, the Highway Patrol said.