cityhall3.jpg9:42 AM: A small electrical fire prompted the evacuation of San Francisco City Hall on Tuesday night, and operations are still affected this morning, a mayoral spokeswoman said.

The fire, reported around 9:30 p.m. in an electrical vault in the basement, activated the building’s sprinkler system, said Christine Falvey, spokeswoman for Mayor Ed Lee.

Those inside the building were escorted out, including hundreds of people who were attending a private reception in the rotunda, she said.

The sprinkler system and responding firefighters quickly extinguished the blaze, but there was minor water damage to the basement, Falvey said.

The city’s Elections Department, which is located in the basement, was not affected by the fire, Falvey said.

The first and second floors of City Hall, which are home to various departments that offer public services, are open for business today, Falvey said.

The third and fourth floors, which mostly contain city staff offices, have intermittent power and a number of employees are working remotely this morning, Falvey said.

She said power is expected to be fully restored to City Hall later this morning.

The cause of the fire remains under investigation.

Dan McMenamin, Bay City News

11:13 PM: The San Francisco Fire Department responded to reports of smoke in City Hall tonight, a dispatcher said.

Firefighters were called to City Hall at 9:26 p.m. on reports of smoke and arrived to find that the building’s sprinkler system had been activated.

The smoke had come from a problem with an electrical panel, according to fire officials, and PG&E crews were called to the scene.

Minimal fire units remain there tonight. Any fire was handled by the sprinklers, according to the Fire Department.

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