A fire that barreled through an apartment building construction site sending up black smoke that could be seen for miles around the San Francisco Bay smoldered into Wednesday morning as authorities worked determine what sparked the destructive blaze, according to AP. The exact cause of the fire - one of the city's largest in recent years - was under investigation, but crews were welding at the site of the blaze, San Francisco Mayor Ed Lee said. The fire appears to have started above ground, according to Lee. Crews prevented flames from spreading to nearby buildings. The fast-moving blaze, which sent an enormous plume of black smoke into the sky, began around 5 p.m. local time Tuesday in San Francisco's Mission Bay neighborhood, a onetime industrial area that lies along the San Francisco Bay and is home to a University of California, San Francisco campus. Crews remained at the scene on Wednesday morning putting out hotspots. Nearby buildings were evacuated as more than 150 firefighters battled the flames, using about 90 fire trucks, the San Francisco Chronicle (http://bit.ly/1cSlq6y) reported. Some front windows of Strata at Mission Bay, a building across the street, blew out from the heat of the fire. Residents of Strata remained evacuated on Wednesday morning. San Francisco Fire Deputy Chief of Operations Mark Gonzales said exterior sprinklers on the building that went off have to be replaced and the fire protection system restored before residents will be allowed back in. The burning building was part of a residential development project with 172 units, according to BRE Properties, the building's owner. Fire-suppression systems had not yet been installed in the building, making the battle more difficult, fire officials said. -- SPA 19:57 LOCAL TIME 16:57 GMT تغريد
