The California Power outage that hit the San Diego area on Thursday afternoon was the most widespread in the history of San Diego Gas & Electric (SDG&E), the utility that provides power to San Diego County and southern Orange County.

It hit 1.4 million customers (the SGD&E serves 3.5 million consumers in total), shut down traffic lights, and put the police and U.S. Customs Border Patrol on backup power.

As earlier 9 p.m. PT on Thursday, some power was restored, according to SDG&E. By 3:26 a.m. PT on Friday, power was restored to most of the 1.4 million affected customers some 12 hours after the initial outage.

For incident of isolated outages, the company urged customers to call 1-800-411-SDGE (7343).

For the next few days, SDG&E will focus on securing the integrity of the system. It also urged customers to conserve electricity as the restoration process has left the local power grid very fragile. Specifically, SDG&E urged people to limit their use of air conditioners.

After its system is secure, the SDG&E will focus on determining the sequence of events that led to the outage and establishing practices and procedures to ensure that outages such as the Sept. 8 event are not repeated.

It has already determined that the cause of the outage stemmed from an operator error that occurred in Arizona.

The error tripped the company's two major power sources, one from Arizona and one from north of the region.

The FBI assure[d] that there was no indication of terrorism, reported East County Magazine.

Arizona California