Rural area in Northern California jolted by its biggest quake since 1940

The area in Mendocino County dotted with small, agricultural towns is 140 miles (225 kilometers) northeast of San Francisco.

Heather Rose, a Mendocino County spokesperson, said that hospitals had reported some injuries but that she had no details on their nature or extent. She said officials plan to meet later Wednesday when more information could be released.

Power outages are affecting more than 6,000 residents of six towns near the epicenter, the Mendocino County Executive Office said in a statement, and encouraged people to stay off the highways and roads to allow work crews to inspect for damage and make repairs.

Brie Leon and her colleagues had just opened Club Calpella Restaurant when the building started shaking, rattling plates and liquor bottles.

"I had just turned the open sign on and went back into the kitchen, and that's when it happened," she said. "It almost felt like something hit the building."

The restaurant is in Calpella, California, a town about 10 miles (16 kilometers) south of the epicenter and in a region of Mendocino County that has been struck by smaller quakes this year.

This was the biggest earthquake in nearly nine decades in the region, which is not on a major fault, said Lucy Jones, a veteran California seismologist.

"The area is not without earthquakes, but they're usually smaller than this," Jones said. She added that aftershocks are likely, but they'll "probably stay on the low side."

Three other quakes under a 2.7 magnitude struck near the epicenter within an hour.

Leon said the quake knocked frames off the walls and bottles off the shelves in the restaurant and the stockroom next door. She and other servers were cleaning up not long after to welcome customers for breakfast.

"It wasn't a big, big quake, but things went everywhere," she said.

Alan Harris and his family were at home in Kelseyville, about 40 miles (64 kilometers) southeast of the epicenter, when he received an earthquake alert on his cellphone. Soon after, the house began shaking.

"I yelled downstairs immediately to my wife and daughter to make sure they were hanging on," Harris said. "It was scary. You could hear things crashing, mostly on the third floor of the house."

A security camera inside Harris' home shook vigorously as the quake struck. A few loud, crashing sounds can be heard on the video footage before Harris calls out: "Is everyone OK?"

It lasted only about 30 seconds. Framed photos fell off the walls and a computer monitor was knocked over, Harris said. Nothing appeared badly damaged, he added, noting he found no structural damage to the house.

Nearly 657,000 earthquake early warning alerts were sent by the MyShake App throughout Northern California, the California Governor's Office of Emergency Services said. Cal OES had not received any reports of damage or injuries but it was coordinating with authorities to evaluate impacts, the office said in a statement.