Summary:
A fire at a construction site in San Francisco has forced the evacuation of hundreds of people, officials said.

Full article:
(CNN) -- Half of the firefighters on duty in San Francisco on Tuesday night were battling a blaze at a construction site that is threatening nearby buildings, authorities said. Officials evacuated "several hundred" residents who live across the street from the blaze, said Mindy Talmadge of the San Francisco Fire Department. "The buildings across the street that are inhabited were evacuated," Talmadge said. "The heat from the fire was making the windows pop and firefighters had to put up a water curtain to protect the buildings." The construction site and the scaffolding around it have collapsed into the site, she said. Authorities said the entire structure will likely collapse due to a combination of water used on the blaze and damage. Mayor Edwin M. Lee said an investigation is under way to determine the cause. "The city and the Red Cross will work closely with any displaced residents of nearby homes," Lee said. "Thanks to the leadership and determined action of our Fire Department, the very real potential of severe damage to other homes, businesses and structures in the neighborhood was avoided." At least 150 firefighters are involved in the blaze at Mission Bay neighborhood. CNN's Mayra Cuevas contributed to this report .