A construction worker on the Twin Peaks Tunnel Project died after being hit Friday by a steel beam, San Francisco Mayor London Breed confirmed.
Patrick Ricketts, 51, of Williams, California, was identified as the signal technician who worked for Shimmick Construction, according to San Francisco Medical Examiner.
Shimmick Construction, a company based in Oakland, did not immediately respond to NBC Bay Area's request for comment.
"We are treating this matter seriously and immediately alerted the Occupational Safety and Health Administration and the San Francisco Police Department to conduct a full investigation so we can better understand what transpired," Mayor Breed said in a statement.
The Twin Peaks Tunnel goes under the Twin Peaks and ends in the West Portal neighborhood. The SFMTA has stopped work on the project due to the accident, Mayor Breed said.