Derion Tradon James Jr., 28, was booked on suspicion of involuntary manslaughter after a woman in her 20s died from injuries suffered in a Fourth of July explosion in Chino.
Police said a large quantity of fireworks ignited around 8:30 p.m. on D Street during a neighborhood display, severely injuring three adults and a child and setting a vehicle on fire.
Three adults were taken to local hospitals with severe injuries; two are expected to survive, while the juvenile was treated and released to a parent or guardian.
Witnesses described a chaotic scene as people fled the blast, and one neighbor said video suggested illegal fireworks may have exploded from a vehicle trunk.
Chino police and the Chino Valley Fire District were still searching the area into early Sunday, with nearby roads closed and the investigation ongoing.