Heads up homeward commuters: several sources are reporting downed Muni cables have closed Market Street to traffic between Fifth and Sixth Streets. Emergency crews are currently on the scene, but at the moment Muni power is cut off from Third to Ninth Streets, as well as part of Mission. No buses are moving up or down Market Street in the area. Passengers should be advised to either head underground to the Muni Metro to avoid the mess topside or find an alternate, non-Market Street route home.

The official word from Muni:

Update 5pm: According to one witness, the power lines struck a car and landed in a crosswalk as they fell. ABC7 is now reporting that at least three people were injured, while KTVU reports a possible fourth:

Muni also reports the F Line is switching back on both ends of the outage: near the Ferry Building as well as 11th and Market. All buses in the area are being re-routed:

Bay City News confirms with the Fire Department that at least two people were taken to the hospital to be treated for minor injuries. According to local tweeter Doc Popular, who snapped the above photo of the scene at Fifth Street, the silver car in the middle of the picture was apparently struck by the falling power lines.

Update 5:45 p.m.: The Chronicle confirms a third injured person and mentions that one pedestrian, a woman in her twenties, was hit when a trolley bus snapped the live wire just after 4 p.m. today. Market Street remains closed to traffic between Fourth and Sixth Streets and is expected to stay closed through the remainder of rush hour.

Muni lines still affected by the outage: 6-Parnassus, 30-Stockton, 45-Union, 31-Balboa, 21-Hayes, 14-Mission, F-Market.

Update 7:40 p.m.: SFMTA reports the power outage has cleared. All buses and F line service have resumed, and shuttles will continue running until schedules are back to normal.