At least six vehicles were involved in a crash on the Riverside (91) Freeway Sunday, prompting a Sigalert to be issued.
The crash was reported at about 11 a.m. on the westbound side of the freeway near Tyler Street, according to the California Highway Patrol.
It was not immediately clear if anyone was injured.
The CHP said the carpool and left lanes would be shut down for approximately one hour.
Traffic was backed up to Van Buren Boulevard, according to Sigalert.com.