The California Highway Patrol reopened all the lanes hours later. Details of possible injuries were not immediately known.
The collision, involving a semi-truck, a sedan and an overturned pickup truck, occurred shortly before 6:30 a.m. near Citrus Street, according to a California Highway Patrol incident log.
One of the vehicles was engulfed in flames after striking a pole on the center divider.
SIGALERT ISSUED IN WEST COVINA: I-10 AT CITRUS ST, WB #1/2 LANES AND ALL EB LANES WILL BE CLOSED UNTIL FURTHER NOTICE DUE TO A TRAFFIC COLLISION— CHP PIO - LA County (@CHPsouthern) September 3, 2018
Crews worked to contain fuel that spilled near one of the burned-out vehicles.
Eastbound traffic was backed up as far as Azusa Avenue. Shortly before 9:30 a.m., all eastbound lanes were reopened as well as the two westbound lanes.
The cause of the crash was unknown.