SAN FRANCISCO (CBS SF) — A construction worker who was injured by a steel beam Friday at the Twin Peaks Tunnel Project has died, San Francisco Mayor London Breed confirmed Saturday.

The worker was hit by the beam about 4:30 p.m., on the West Portal site of the tunnel, according to the San Francisco Municipal Transportation Agency. He was taken to Zuckerberg San Francisco General Hospital.

READ MORE: UPDATE: Evacuation Orders Downgraded to Warnings as Crews Mop Up Estrada Fire Near Watsonville

“We are saddened to hear about the passing of a signal technician who was working in the Twin Peaks Tunnel yesterday evening,” Breed said in a statement.

“Our sincerest condolences are with his family, friends, and colleagues at this time.”

READ MORE: Pleasant Hill Police Ask Public for Help Finding Stabbing Suspect

“This is a tragic incident and I want to commend the Twin Peak Tunnel laborers who quickly sprang into action to help their colleague,” the mayor said.

The worker, whose name has not been released, died Friday night and was employed by Oakland-based Shimmick Construction, San Francisco Municipal Transportation Agency officials said.

Work on the tunnel has been suspended and the Occupational Safety and Health Administration has been alerted, officials said.

MORE NEWS: Alameda Police Seek Person of Interest in Friday Night Shooting

© Copyright 2018 CBS Broadcasting Inc. and Bay City News. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed