The strongest earthquake in 25 years struck in Northern California early Sunday, injured dozens of people and several historic buildings damaged in downtown Napa
An earthquake with a magnitude of 6.0 has shaken northern California
The USGS said it struck at 03:20 local time (10:20 GMT) four miles (6km) north-west of the town of American Canyon, at a depth of 6.7 miles.
At least 172 people have been taken to hospital in the Napa area, a renowned wine-producing region and tourist area.
California Governor Jerry Brown has declared a state of emergency in order to deal with the effects of the quake.
Officials in Napa said in a statement that the quake – believed to be the biggest in the region in 25 years – had destroyed four mobile homes and made 16 buildings “uninhabitable”, as well as causing “approximately 50” gas main breaks and around 30 leaks from water mains.