Residents of this picturesque wine-making area north of San Francisco have been warned to be careful around buildings damaged by a weekend magnitude-6.0 quake because of the danger of aftershocks that could continue for several weeks.
The quake struck early Sunday about six miles south of Napa, according to the U.S. Geological Survey.
It was the largest to shake the San Francisco Bay Area since the magnitude-6.9 Loma Prieta quake struck in 1989, collapsing part of the Bay Bridge roadway and killing more than 60 people, most when an Oakland freeway fell.
At least 172 people were treated for injuries at a hospital, and three were in critical condition. One of the most serious cases was a child who was airlifted to UC Davis Medical Center in Sacramento, the San Francisco Chroniclereports.
The boy had been hit by debris from a falling chimney. Also in critical condition was one person who suffered a heart attack and one with a broken hip.
The quake, which knocked out power to thousands of people and hit the wine-making industry on the eve of its harvest, could result in more than $100 million in losses.
Guests in the five-story Andaz Napa hotel, one of the tallest structures in the city, were immediately evacuated, many remaining on n the sidewalk, with their luggage, even hours later, wondering about alternative accommodations, the Napa Valley Register reports.
One guests, Cheryllyn Tallman, told the newspaper that was so shaken she planned to cut shot her wine country vacation and head back home to the East Coast.
"I live in Upstate New York," Tallman said. "We just have blizzards — and they tell you when they are coming."
Gov. Jerry Brown declared a state of emergency for Napa, Solano, and Sonoma counties. Schools in Napa Valley were ordered closed Monday.
By midday Sunday, fires -- including one that destroyed four homes at a mobile home park -- were out and power was starting to be restored, said Mark Ghilarducci, director of the California Governor's Office of Emergency Services.
"While it was bad, it wasn't as bad as it could be and it was very manageable from a regional perspective," Ghilarducci said.
Pacific Gas and Electric said Monday afternoon that electric service was restored to all 70,000 customers who lost power in the quake.
Residents, however, were bracing for aftershocks that usually follow big temblors.
On Sunday night in Southern California, a small, magnitude-3.3 earthquake hit off the region's coast. The U.S. Geological Survey says the temblor struck at 7:50 p.m. and was centered about 5 miles southwest of San Pedro and 6 miles southeast of Rancho Palos Verdes. There were no initial reports of damages, police said.
State Geologist John Parrish says the aftershocks will decrease in magnitude and that it is unlikely there would be a large follow-up earthquake. Still, he warned people to be careful because newly damaged buildings are now more susceptible to collapse from aftershocks.
About 15 buildings were damaged too severely to allow people inside, and many more awaited further evaluation. Ghilarducci, said 90 to 100 homes and buildings were deemed uninhabitable.
Wine and olive oil bottlers suffered damage. Hundreds of broken bottles littered the floor of Lucero Olive Oil, but owner David Gadlin said the store would reopen Monday as usual.
"A lot of downtown business owners will be back up and running," he said. "There's been financial hardship, but we'll get through it. Few people were hurt. That's what's important."
Lou Ishaq said at a service station he owns that he had a major cleanup job and had to get a battery from Sacramento, but managed to start pumping gas again.
"I think we'll recover pretty quick,'' he said. "The people who sustained major structural damage will have the worst of it. But everyone else, it's just clean up, assess your losses and get going."
Bertha Flores, 40, was out buying ice to keep the food in her refrigerator cold as her family waited for the power to come back on.
Speaking in Spanish, she said the earthquake frightened her children, but everyone was OK except for some cuts from shattered glass.
"I'm a cleaner. I think there is going to be a lot of work for my company in the next couple of days,'' she said.
Contributing: Greg Toppo, Donna Leinwand Leger, Katharine Lackey, Marisol Bello and Doyle Rice from McLean, Va.; Catalina Camia from D.C.; William M. Welch from Los Angeles; Laura Mandaro from San Francisco; Associated Press