PG&E has confirmed that a major fire inside a key San Francisco power substation caused extensive damage, triggering one of the city’s largest recent blackouts. Utility officials say the damage was severe, calling repairs highly complex and warning that full restoration could not be rushed due to safety concerns. The outage left more than 130,000 homes and businesses without power, disrupted transit systems, forced widespread business closures, and even caused self-driving cars to stop mid-street as traffic signals failed.