San Francisco fire officials said Monday that TC Steel of Petaluma was the subcontractor whose work is believed to have started the five-alarm blaze at a construction site in The City's Mission Bay neighborhood in March.
Fire officials said TC Steel's president, Tom Cleary, has been cited and fined $1,000 for being out of compliance with The City's fire code.
The company was doing hot work welding at the construction site at 1200 Fourth Street, according to fire officials.
The massive blaze destroyed a 172-unit, six-floor residential complex at 1200 Fourth St. on March 11.
San Francisco fire officials said in a recent report that the fire was accidental and occurred after "an event involving a wire welding unit or grinder between the top floor and the 'high roof' area."Cleary and other TC Steel officials couldn't immediately be reached for comment.