SANOMA, Calif. (AP) -- Officials say an earthquake with a preliminary magnitude of 6.0 has been reported in California's northern San Francisco Bay area.
Leslie Gordon of the U.S. Geological Survey says it struck at just before 3:30 a.m. Sunday about 10 miles northwest of American Canyon, which is about six miles southwest of Napa. The USGS says it's the largest earthquake to shake the Bay Area since the 1989 6.9 magnitude Loma Prieta quake.
The shaking set off car alarms and had residents of neighboring Sonoma County running out of their houses in the middle of night. Officials say widespread power outages have been report in Sonoma County.
The USGS says the depth of the earthquake was just less than seven miles, and numerous small aftershocks have occurred in the Napa wine country.
A member of Napa County dispatch tells The Associated Press that there has been one report of structural damage, but additional details were not available.
There was no immediate report of injuries.