A big rig overturned Wednesday morning on the southbound Golden State (5) Freeway in Sun Valley and the wreckage was blocking lanes of traffic.
The crash occurred near Glenoaks Boulevard about 2:20 a.m., according to the California Highway Patrol.
The trailers detached from the cab when the semi overturned, prompting the closure of the carpool and Nos. 1 and 2 lanes of the freeway until further notice, the CHP said.
No injuries were immediately reported.
It was unclear what caused the semi to overturn.