Firefighters responded to the scene in the Garden Grove area around 7 a.m. and found one victim already deceased.
Authorities said the three-vehicle crash occurred when a passing vehicle struck a passenger from another vehicle that was disabled on the freeway's shoulder. The passing vehicle then rammed into a wall and triggered a three-car chain reaction crash.
The man who was struck in the initial collision was the victim found dead at the scene.
The three injured victims were transported to area hospitals. Two were listed with traumatic injuries.
The cause of the crash is under investigation by the California Highway Patrol.