A violent chain-reaction crash shut down the 210 Freeway in Irwindale on Saturday morning after a big rig traveling eastbound lost control, crossed the center median and slammed into oncoming westbound traffic, leaving one woman dead and more than 30 people injured.

The crash unfolded shortly before 9 a.m. just west of Irwindale Avenue, according to a California Highway Patrol incident log.

Officials said at least three vehicles were involved in the wreck, though investigators noted the total number was still unclear.

Authorities said the semitruck, which had jackknifed during the incident, punched through the median barrier and struck a vehicle heading in the opposite direction, setting off a multi-car pileup that brought both sides of the freeway to a standstill.

A woman was pronounced dead at the scene. Her identity has not yet been released.

Emergency crews reported that 10 people were taken to nearby hospitals, including two in critical condition and eight with minor injuries.

The chaos forced a massive shutdown of the roadway, with all westbound lanes closed and three eastbound lanes blocked, causing heavy traffic backups in both directions.

In a social media update, the California Highway Patrol said lanes would remain closed “for an unknown duration” as investigators worked to determine what caused the crash.