There was an unplanned power outage in central San Francisco Thursday morning that was impacting almost 4,000 households and businesses in the Castro, Corona Heights, and Cole Valley neighborhoods.

The power went out just before 10:30 am for a swath of San Francisco that included part of Castro Street in the Castro neighborhood, much of 17th Street west of Castro toward Corona Heights, as well as Cole Valley, part of Clarendon Heights, and Forest Knolls.

In a standard statement on their website, PG&E says the outage was unplanned, and says "Our team is evaluating the electrical system to identify damaged sections and make necessary repairs in order to safely turn the power back on."

An estimate for power restoration was 2:30 pm, meaning the outage could extend to four hours.

A total of 3,996 customers are reportedly impacted. And there is no word on what may have caused this outage.

See the outage map below.

This is a developing story.