UPDATE — 1:30 p.m. PT:
The U.S. Geological Survey has confirmed a 6.0-magnitude earthquake struck Northern California in the early hours of Sunday morning.
Earthquake near San Francisco/Sacramento rocks buildings, shatters glass, Twitter users report http://t.co/oDy3rKPBto
The earthquake took place about 6.6 miles below the surface about 6 miles from Napa, California, the USGS reported. Between 25 and 60 smaller aftershocks are expected in the area over the next week.
More than 42,000 customers lost power in the northern Bay Area, according to PG&E. Towns include American Canyon, Napa, Saint Helena, Santa Rosa, and Sonoma.
"It was a rolling quake," Oakland resident Rich Lieberman told the AP. "It started very much like a rolling sensation and just got progressively worse in terms of length. Not so much in terms of shaking, but it did shake. It felt like a side-to-side kind of rolling sensation. Nothing violent but extremely lengthy and extremely active."
Wine section at Safeway in American Canyon
Power out as far as the eye can see here in Sonoma. Heard one emergency siren a few min ago but otherwise silence and darkness.
More than 100 people were sent to the hospital with non-life threatening injuries, the Associated Press reported.
Most of the patients at the Queen of the Valley Medical Center in Napa had cuts, bumps and bruises, a spokesman said. Three people had broken bones, and two people had heard attacks. One child was in critical condition after being struck by part of a fireplace, the AP reported.
At least four homes were destroyed in a fire at a mobile home park, with a water main break making it difficult to put the fire out, Napa Fire Capt. Steve Becker told the San Francisco Chronicle.
Residents say everyone got out safely. Firefighting hampered because water main burst. Had to truck in water.#mapit
Along with the minor injuries, ABC News is reporting two "major injury cases."
City of Napa, Calif., says 2 "major injury cases" among dozens of people being treated for injuries after earthquake - @ABC LA
What a wake up call, scariest thing of my life,glad we r ok! PQP q susto o terremoto aqui na California
Images depicting the damage around Napa have appeared on social media.
Earthquake at @SilverOak
This is interior of Don Pericos restaurant in Napa.
Two trapped when this home shook off foundation in Napa. Neighbors helped them out as fire started 2 homes down.
Fire in Napa at a mobile home park. Water main break and firefighters without water. At least two homes destroyed.
Meadowbrook Lane in Napa-- skaters finding upside to quake damage. Photo from #nbcbayarea photog Jeremy Carroll
Sunday's earthquake was the highest magnitude one in years. The Independent reports:
In 1989 an earthquake measuring 6.9 struck the Santa Cruz area of California, killing 62 people, according to government figures.
Prior to that one there had been quakes of 5.7 and 5.8 in 1983 and 1980 respectively.
Richter Scale- works exponentially, which is why 1989 6.9 #BayArea #earthquake 10x stronger than today's 6.0 #sfquake