One person died after a "chain-reaction" caused a four-vehicle crash and SigAlert on the 60 Freeway in Diamond Bar Sunday morning.
Responding officers began arriving to the scene on the eastbound 60 Freeway between Fairway Drive and Brea Canyon Road around 4:30 a.m.
The chain reaction began after two vehicles crashed and became disabled in the carpool and adjacent lane, leaving a white SUV vehicle facing the wrong way, California Highway Patrol Officer Robert Reyes said.
A third vehicle then crashed head-on into the SUV, causing it to catch fire.
Multiple passengers attempted to extricate the trapped SUV driver when a fourth vehicle became involved.
"As they were assisting the driver of the SUV a fourth vehicle in the HOV (high-occupancy vehicle) lane struck what were essentially pedestrians," Reyes said.
One person died and at least two sustained major injuries, he said. CHP Officer Tony Polizzi previously said three were critically injured.
All lanes on the eastbound 60 Freeway were closed and a SigAlert was issued around 5 a.m.
The SigAlert was cancelled around 8 a.m., CHP tweeted.