An underground equipment failure is the reason 2,500 people in the Rossmoor area of Walnut Creek lost power about 6:35 p.m. Wednesday, according to PG&E spokeman Jason King.
He said there were three separate outages, which affected a total of 2,500 homes and businesses.
"It was a series of failed connectors on an underground line near the Rossmoor community," King said.
The majority of customers had power restored by 8 p.m., he said. The rest were back up as of 11 p.m. Wednesday.
