Power utilities in some of the most populous areas of the United States are thanking customers for their patience and explaining what caused several major outages in San Francisco and New York City last week.
Pacific Gas & Electric said the outage affecting 90,000 people Friday was caused by a failing circuit breaker that triggered a substation fire. PG&E spokespeople said the equipment was scheduled for repair, but failed before the planned repair.
There were no injuries reported with this outage.
In New York City, Con Edison pinpointed the cause of a blackout that shut down most of the city's subway system Friday.
The power failure was traced to the 7th Avenue-53rd Street Station in Manhattan. The failure caused hundreds of subway users to be stranded in the dark.
In both San Francisco and New York, backup generators power prevented too much chaos.