California wine country rocked by 6.0 quake, dozens hurt

(Adds quotes, updates number of patients treated, adds number of houses in Napa not safe to enter)

By Jim Christie

NAPA, Calif., Aug 24 (Reuters) - A 6.0 magnitude earthquake rocked wine country north of San Francisco early on Sunday, injuring more than 100 people, damaging historic buildings, setting some homes on fire and causing power outages around the picturesque town of Napa.

The quake, the biggest in the region in 25 years, jolted many residents out of bed when it hit at 3:20 a.m. (1020 GMT). It was centered 6 miles (10 km) south of the city of Napa, which is located about 50 miles northeast of San Francisco.

There were no known fatalities, but three people were seriously injured, including a child who suffered multiple fractures after a fireplace fell on him, local fire battalion chief John Callahan said. Six fires broke out, including one that consumed six mobile homes, he said.

Queen of the Valley Medical Center in Napa said it had treated 120 patients injured in the quake, which was strong enough to be felt throughout the San Francisco Bay Area.

"They say it went for 50 seconds. It felt like 50 minutes. I was just too terrified to even scream," said Patricia Trimble, 50, the owner of an antique store. She rushed to her store in central Napa and found the front window blown out, cabinets on their sides and merchandise littering the floor.

(Graphic on the Napa quake: http://link.reuters.com/tud72w)

California Governor Jerry Brown declared a state of emergency, putting all state resources at the disposal of his Office of Emergency Services.

Despite the force of the quake, it ranks as only moderately strong.

California, which sits along a series of seismic faults, is forecast to experience a much more powerful earthquake at some point, but scientists do not know when it might come or how strong it would measure, a geophysicist with the U.S. Geological Survey (USGS), Don Blakeman, said.

"Usually when people talk about 'The Big One,' they're talking about something on the order of a magnitude 9, which of course is tremendously more powerful" than Sunday's quake, he said.

The biggest impact was centered around Napa, a famous wine-producing region and a major tourist destination in northern California.

Brick facades gave way in the historic section of downtown Napa, a city of 77,000, and bricks fell off a second floor corner of the courthouse, which showed cracks. On the main street, masonry collapsed onto a car.

One building housing winery tasting rooms had to be closed to tourists, and the floors of many wine stores were stained red from the contents of broken wine bottles.