The violent collision, which left a Chevrolet Avalanche overturned, was reported at 4:22 a.m. at Slauson and Boer avenues, according to the California Highway Patrol. A second Chevrolet pickup and a Ford Fusion sedan were also severely damaged.
Two men were pronounced dead at the scene, said a spokesperson for the Los Angeles County Fire Department. A third person was transported to a hospital in unknown condition.
The names of the deceased, who were inside the destroyed Fusion, were later released. They were identified as Moises Duran, 28, and Christopher Rivera, 30.
According to investigators, the Fusion veered into oncoming lanes and collided with the two pickups. The impact caused the Avalanche to roll over onto its roof. The other truck veered off the road and onto the sidewalk.
Authorities said they believe another vehicle, possibly a gray or silver BMW, may be involved in the crash and are not ruling out the possibility that street racing may have been a factor.
A section of Slauson was closed as the investigation continued at the scene, where debris from the mangled vehicles littered the street.
Authorities were looking for witnesses. Anyone who saw something was asked to contact the CHP.
CORRECTION: An earlier version of this story stated the location was Pico Rivera. The accident happened in an unincorporated area of Whittier.