A power substation at Pacific Gas & Electric prompted an outage in San Francisco, shutting down traffic lights, cable cars, Muni service and BART on Friday leaving around 90,000 utility customers without power.

The series of outages started around 9 a.m., according to PG&E spokesperson Tamar Sarkissian.

The outage area extended from the Tenderloin to Chinatown, the Marina, Nob Hill, and the Financial District, including BART’s downtown Montgomery Station and all the way to the Presidio.

Barry Anderson, also a PG&E spokesman, said the outage was caused by a circuit breaker at a large substation.

“We had equipment failure, the catastrophic failure of a circuit breaker,” said Anderson. “When it failed, it created a fire in the insulation surrounding the breaker; something went wrong with the breaker to cause it to explode.”

According to Anderson, the Larkin substation where the equipment failed was previously identified as needing renovations in 2017-2018.

What was originally a $100 million dollar job will now most likely result in a bigger price tag due to the severity of the damages.

“The equipment failed before we could get to the upgrade,” said Anderson.

According to Mayor Ed Lee there were no reported injuries.

“Big Lesson: backup generators,” said Lee at a news conference. “It worked.”

Around 4 p.m., at the start of the typical evening commute, power was restored.

Another power outage was reported Friday in New York City, which lasted until approximately 11:30 a.m. and caused major subway delays. Los Angeles also experienced smaller, sporadic outages in different areas of the city and at Los Angeles International Airport.

The outage in New York occurred shortly after an Infrastructure Report Card gave both mass transit and power systems poor grades.

Map of San Francisco’s power outage at 10:45 a.m. on April 21, 2017. (Source: PG&E)

#poweroutage no shops open in Union Sq. No street lights. Avoid area pic.twitter.com/dF2iAy9Paw

— Louisa Pickering (@loulousfo) April 21, 2017

SF #PowerOutage totally surreal pic.twitter.com/PyIMQYBVN8

— Dylan Gale (@dylanmgale) April 21, 2017

The power outage in SF is generating multiple calls for service which #yoursffd is handling We have seen no injuries as a result so far. pic.twitter.com/uESEuO9ESQ

— San Francisco Fire (@sffdpio) April 21, 2017