A big rig crashed, jackknifed and overturned Sunday evening on the Foothill (210) Freeway in Glendora, blocking four freeway lanes.
The crash happened around 8:40 p.m. on the westbound 210 Freeway at Sunflower Avenue, according to the California Highway Patrol.
The crash shut down four lanes, leaving only the carpool lane open, according to the CHP.
The CHP issued a SigAlert at 9:11 p.m. It was unknown how long the lanes would remain shut down.
No injuries were immediately reported.