Armando Murillo, 28, of Pacoima, was a passenger in a pickup truck when a tractor-trailer slammed into it Saturday morning.
Murillo and the driver of the pickup were trapped inside as the truck was lodged underneath the 18-wheeler.
Murillo was pronounced dead at the scene.
The driver of the pickup was taken to the hospital and was expected to survive.
Authorities responded to the scene near 37th Street and Santa Fe Avenue at about 3:10 a.m., according to Vernon police.
Investigators said the driver of the 18-wheeler was involved in a minor crash near Soto and 37th streets before he ran a red light and collided with a pickup truck, which was found mangled underneath the trailer of the big rig.
Authorities said the driver dragged the heavy pickup truck for several feet before stopping, jumping out and unhooking the cab from the trailer to flee the scene.
A person of interest, Guillermo Ortiz Jr., is believed to have information on the crash and authorities want to speak with him.