SAN FRANCISCO (AP)
San Francisco Mayor Ed Lee says crews were welding at the site of a massive fire that engulfed a construction site, forcing evacuations and threatening nearby buildings.
The exact cause of the blaze is under investigation. But Lee said on Wednesday the fire appears to have started above ground, and there was welding going on.
The blaze began around 5 p.m. Tuesday at an apartment building that was under construction. Crews were able to keep the blaze from spreading.
But it forced the evacuation of a building across the street and sent an ember onto the roof of another building.
Two firefighters suffered minor injuries.
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