San Diego, September 9, 2011 — About five million people in Southern California, Arizona and Mexico were enveloped in a power outage September 8, with officials saying the blackout could last a day or more as work is done to correct the problem.
The outage was attributed to human error, according to reports, and could have been triggered by a utility employee working on a substation in Arizona. The blackout so far has caused traffic jams on California freeways and disabled water services in San Diego and Tijuana.
San Diego Gas and Electric said in a tweet that 1.4 million electricity customers in the San Diego service area are without power. Another 3.5 million in the Baja California area are also in a blackout. Yuma, Arizona has also reported outages for about 50,000 people.
Such an outage has never before happened to the San Diego service area, according to SDG&E.
The cascading power failure was caused by a botched maintenance procedure that resulted in the shutdown of a transmission line supplying power to the San Diego area. This, in turn, interrupted the power flow from California’s 2,200 MW San Onofrenuclear power plant, according to SDG&E.
Arizona Public Service said human failure and system failure were to blame for the outages.
By late September 8, crews restored service to the transmission line that set off the blackouts and were working on restoring power to San Diego County.
As of press time, power had been restored to about 165,000 customers in San Diego and Orange counties. Utilities are instructing customers to conserve power as the restoration effort continues.