SAN DIEGO (AP) -- An employee at a power substation in southwest Arizona likely caused a massive outage that left more than 2 million people without electricity across the Southwest and northern Mexico.
Power officials in Arizona said the employee was carrying out a procedure at a substation in North Gila northeast of Yuma. They didn't immediately explain the procedure.
Authorities say the outage should have been limited to the Yuma area. They were investigating why it wasn't contained.
Most of San Diego lost power, as well as cities south of the border and about 56,000 people throughout Yuma and the surrounding areas.
Arizona Power Services President and CEO Don Robinson say they are working to restore power as soon as possible.