(ABC News) - A 6.0 magnitude earthquake damaged building, knocked out power to thousands in northern California this morning and injured dozens of people, some critically.
The South Napa Earthquake struck about 3:20 a.m. local time, according to the U.S. Geological Survey. It's epicenter was located about six miles south-southwest of Napa, California, and 51 miles west-southwest of the state capital, Sacramento.
Dozens of aftershocks followed, with one reaching 3.6 magnitude, the USGS told ABC News. The earthquake was the largest one to shake the Bay Area since the 1989 6.9 magnitude Loma Prieta Earthquake.
Pacific Gas and Electric Company showed more than 15,000 customers without power, primarily in Napa, Sonoma and Santa Rosa Counties.
ABC News station KGO in San Francisco reported several fires and damaged buildings in Napa.
Eighty-seven people were being treated at Queen of the Valley Medical Center in Napa, Napa City Fire’s Darren Drake told ABC News. Three of those people were considered critical, including a child.
Dozens of ambulances have been dispatched and more were expected to go out, he added
The city of Napa's website said the injuries included two "major injury cases" as of 6:30 a.m. PT. The city also cited 50 gas line breaks and 30 water main leaks, though said water remained safe to drink.
Historic buildings damaged included Sam Kee Laundry, Goodman Library and the Napa County Courthouse, the city said, adding that two commercial buildings also had suffered severe damage.
Napa County Supervisor Bill Dodd said he believed the county courthouse had been retrofitted for earthquakes.
"I've been through a few of these and I've never seen anything like this, particularly in downtown Napa," Dodd said, according to ABC News Radio. "The county building is just in total disrepair, and they've moved it down to the sheriff's office -- so that's where the coordinating all the emergency services for the county."
Assistant to the President for Homeland Security and Counterterrorism Lisa Monaco has briefed President Obama on the earthquake, a White House spokesman said.
Dozens living in the region reported falling dishes and violent shaking inside their homes.
"I was alone in the house so I didn't know what to do -- and the first thing when it stopped I ran under the table and tried to get cover because it's the first thing they say to do for an earthquake is get under the table," Diana Martini, who lives in Valejo, California told ABC News.
Martini said her television crashed to the ground, along with some of her dishes.
"I'm on the first floor, so that was the scariest thing. I thought the building was going to come down," she said.
Dozens of social media users also posted photos and videos of damage inside their homes.