The incident was reported at 10:22 a.m. on the NB 710 Freeway at Anaheim Street.
The California Highway Patrol issued a Sigalert, shutting down the area near 9th Street for several hours.
The big rig hit an overpass and spilled its load of machinery.
AIR7 HD was above the scene showing materials scattered across the road. No injuries were reported.
All of the truckers traveling off the shoreline were stuck in traffic, backed up to the Long Beach International Gateway Bridge.