Circuit breaker failure sparks fire at San Francisco substation, cutting power for hours

On 21 April 2017, a fire broke out at a Pacific Gas and Electric Co. (PG&E) substation at Larkin and Eddy Streets in the Tenderloin neighbourhood of San Francisco. PG&E said the blaze was caused by the massive failure of a circuit breaker. The fire knocked out power for about seven hours to much of downtown and northern parts of the city, stranding people in elevators. The San Francisco Fire Department responded and the fire reportedly smouldered for about 90 minutes while crews worked to contain it, ultimately using their own CO2 truck to extinguish it. A subsequent City Hall hearing raised concerns about the delay in notifying city officials, the availability of firefighting agents on site, and firefighter familiarity with the substation. PG&E said it was conducting a root cause investigation expected to take six to eight weeks and would share findings with the city. The substation was already undergoing a planned $100 million overhaul at the time.

PG&E stated the fire was caused by the failure of a circuit breaker. City officials noted a lack of regular fire department inspections or drills at substations, insufficient chemical firefighting agents on hand, and delayed notification to city emergency officials after the fire started.

1. Utilities and local fire services should conduct regular joint training and site familiarisation exercises at substations rather than only after an incident occurs.
2. Adequate firefighting agents and equipment suited to electrical fires should be pre-positioned at substations, particularly those in dense urban areas.
3. Clear, rapid notification protocols between utilities and emergency management officials are essential to limit confusion and delay during outages.
4. Independent oversight and regular third-party inspection of ageing grid infrastructure can help identify failure risks before they cause fires or outages.

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