Ninth Street was closed at about 3 p.m. between Mission and Market streets while a handful of firefighters cleaned up the glass with janitor-style brooms and shovels, battalion chief Charles Krane said.
Krane said wind blowing through the corridor created negative pressure, which blew out a Ninth-street-facing window about 10 stories up on the northwest corner of the building.
He said the area gets some of the strongest winds in the city.
"And the higher you get, the faster the wind is," he added. Wind gusts reached more than 40 mph this afternoon in San Francisco, a National Weather Service forecaster said.
San Francisco police helped keep motorists and pedestrians off of Ninth Street while the glass was cleaned up.
The street was reopened at about 3:30 p.m.
