Dark day for San Franciscians as power cut blacks out city

A power cut in San Francisco that trapped people in lifts and left tens of thousands of others in the dark was caused by a massive failure of a circuit breaker that set off a fire at a power sub-station.

Just after 5pm local time on Friday, Pacific Gas & Electric said power had been restored to all 90,000 customers who lost it in the city's Financial District and other areas.