SAN FRANCISCO – San Francisco fire officials say a massive blaze that barreled through an apartment building construction site last month was accidental, not arson.
In a report released Tuesday, investigators say the five-alarm fire on March 11 in the city's Mission Bay neighborhood began when a hot or smoldering object ignited wood that was part of the building's structure.
Fire spokeswoman Mindy Talmadge said a more detailed report that could explain what caused the blaze is expected in the next couple of weeks.
Fire officials said a day after the fire that they were looking into preliminary reports that workers at the block-long site were doing torch work.
The fire threatened nearby structures and prompted evacuations as firefighters worked to prevent its spread through the neighborhood.