A 6.0-magnitude quake jolted the Bay area early Sunday morning, causing some road closures and damaging at least one building in the Napa Valley, but no injuries have yet been reported.
The quake struck near southwest of Napa at 3:20 a.m. causing houses to shake in the center of San Francisco and knocking out power to more than 50,000 houses.
The earthquake is the largest earthquake to shake the Bay Area since the 6.9 magnitude Loma Prieta quake in 1989, the USGS said.
