Manhole blast in SF Financial District triggered by hydrant burst

An underground explosion sent a manhole cover flying into the air on Wednesday in San Francisco’s Financial District, startling workers and residents amid the morning hustle and bustle in the busy area, officials said.

The heavy metal cover blasted into the air and was followed by a plume of smoke around 8:15 a.m. on Bush Street between Montgomery and Kearny streets near Belden Place, firefighters said.

A manhole cover blasted into the air and was followed by a plume of smoke around 8:15 a.m. on Bush Street between Montgomery and Kearny streets near Belden Place. A manhole cover blasted into the air and was followed by a plume of smoke around 8:15 a.m. on Bush Street between Montgomery and Kearny streets near Belden Place. Photo: San Francisco Fire Dept. Photo: San Francisco Fire Dept. Image 1 of / 5 Caption Close Manhole blast in SF Financial District triggered by hydrant burst 1 / 5 Back to Gallery

The explosion was likely caused by some sort of electrical problem after a fire hydrant burst at Belden Place and Bush Street and gushed into the underground electrical vault about two hours earlier, said Andrea Menniti, a spokeswoman for Pacific Gas and Electric Co.

Firefighters at the scene did not find an active fire burning while PG&E crews descended into the cavity to survey the damage, officials said.

Drivers were told to expect delays, and if possible, to avoid the area.

Twitter user Zach Thomas noted the startling sound and fired off a message.

“Just heard/felt a large noise in the Financial district of San Francisco,” he tweeted. “Anyone know what caused it?”

Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky