It happened at the intersection of Marine Avenue and Sepulveda Boulevard just before 11 p.m. on Tuesday.
Police say a total of four vehicles were involved in the crash, though it's unclear what caused it. Investigators say at one point, one of the vehicles crashed into a nearby building.
Two men and a woman were killed and three others were sent to the hospital in unknown conditions. Among those hospitalized was a child, according to police.
The impact of the crash left a trail of debris along the streets.
As of Wednesday morning, Sepulveda Boulevard was still closed as officers continued their investigation.