Power went out at homes and businesses in the area around 7:30 a.m. and officers closed Crow Canyon Road at Alcosta Boulevard, San Ramon police said.
PG&E officials said all customers had power restored by 9:45 a.m.
Police had initially said a blown transformer was to blame for the outage, but PG&E officials said the cause is under investigation.
MAJOR TRAFFIC ALERT - Crow Canyon is closed in both directions at Alcosta due to blown transformer. @PGE4Me is already on scene for repairs. pic.twitter.com/fT9kkZH6Xv
— San Ramon Police (@sanramonpolice) November 17, 2016
Early estimates say the blown transformer has cut power to roughly 26,000 in the San Ramon Valley.
— San Ramon Police (@sanramonpolice) November 17, 2016
It is estimated Crow Canyon Road will remain closed in both directions at Alcosta Blvd for a minimum of two hours. pic.twitter.com/HeFbseYC0a
— San Ramon Police (@sanramonpolice) November 17, 2016