An earthquake with a magnitude of 6.0 has shaken northern California.
The USGS said it struck at 03:20 local time four miles (6km) north-west of the town of American Canyon, at a depth of 6.7 miles.
California Governor Jerry Brown has declared a state of emergency.
Officials in Napa said that the quake believed to be the biggest in the region in 25 years had destroyed several homes and buildings.
By Sunday evening, between 11,000 and 15,000 people were still reported without power, down from 70,000 people in the immediate aftermath of the earthquake.
In Napa Valley, several motorways, at least two roads and a bridge have been closed.
Please be prepared for traffic disruptions and possible delays in mail processing and delivery.