A pedestrian was struck by a vehicle on the westbound side of State Route 54 at Reo Drive in National City, according to police.
The pedestrian was running northbound across lanes when they were hit near the first lane of SR-54 at 7:20 p.m. Several other vehicles were involved.
The patient was transported to Mercy Hospital with serious injuries, according to officials.
California Highway Patrol has issued a SigAlert and has closed all westbound lanes of SR-54 at Reo Drive while they conduct their investigation.
Police is assisting with traffic control.
Check back for updates on this story.