Underground transformer fire disrupts power in San Francisco

What happened

A KTVU report dated 26 April 2023 said an underground transformer had caught fire the previous night, around 9 p.m., at Clay Street near Montgomery in San Francisco. Pacific Gas & Electric said the fire burned electrical wiring and circuits underground and cut power to nearly 10,000 customers in the Financial District, Marina, Russian Hill and parts of Chinatown. Some customers were restored overnight. As many as 6,000 were still without power early the next morning, and nearly 500 remained off supply late that afternoon.

The city's Emergency Operations Center was activated and was working with PG&E. The utility had hoped to restore power by noon; its outage map that evening indicated some locations might not be restored until 11 p.m. the following night.

Contributing factors

The cause of the transformer fire was not reported.

Lessons learned

1. An underground transformer fire can damage nearby wiring and circuits and leave thousands of customers without power well into the next day.
2. Early restoration times should be treated as estimates until the extent of underground damage is known.
3. Utilities and city emergency centres should share outage extent and expected restoration times with affected districts.

Source

ktvu.com