Underground transformer catches fire, knocks out power for thousands in San Francisco

Parts of downtown San Francisco remain without power on Thursday after an outage from the night before knocked out power to nearly 10,000 customers.  

Pacific Gas & Electric said the outage stems from an underground transformer fire Wednesday night at Clay Street near Montgomery. The transformer burned up electrical wiring and circuits underground, knocking out power around 9 p.m. 

Power was restored to some customers in the overnight hours. However, as many as 6,000 customers were still without electricity early Thursday morning. 

Nearly 500 customers remained without power late Thursday afternoon. 

San Francisco's Emergency Operations Center has been activated to determine the extent of the outage and is working with PG&E. 

Neighbors saw the smoke and flames when it happened.

"It was a popping explosion and then the purple flames started to come out," Douglas Widner said.

The outages are in the Financial District, Marina, Russian Hill and parts of Chinatown. 

PG&E had hoped to restore power by noon. The PG&E outage map, as of Thursday evening says some of these locations won't have power restored until 11 p.m. Friday night.