FERNDALE, Calif. (NewsNation) — A strong earthquake shook a rural stretch of Northern California early Tuesday, killing two and injuring 11 others, according to the Humboldt County Sheriff. The quake also cut off power to approximately 70,000 people and damaged some buildings and a roadway.

The magnitude 6.4 earthquake occurred at 2:34 a.m. near Ferndale, a small community about 210 miles (345 kilometers) northwest of San Francisco and close to the Pacific coast. The epicenter was just offshore at a depth of about 10 miles (16 kilometers). Numerous aftershocks followed.

The Humboldt County Office of Emergency Services initially tweeted that there were reports of “widespread damages to roads and homes,” but authorities subsequently indicated there were pockets of significant damage yet overall it was less than what might be expected from the size of the temblor.

The region is part of California’s lightly populated far north coast, home to redwood forests, mountains, a port and a state university. Long before the state legalized marijuana, Humboldt was part of the three-county Emerald Triangle where clandestine cannabis production was legendary.

Authorities closed an important bridge in Ferndale that was showing damage. The state highway department tweeted a photo showing crumpled pavement.

State Sen. Mike McGuire, who represents the area, said the small city of Rio Dell, home to just a few thousand people, sustained most of the damage. McGuire said he was not in the area at the time of the earthquake, but received reports of “violent,” sustained shaking.

There was one confirmed structural fire, a few structures came off their foundations, and the municipal water system was damaged but it was unclear if any homes and businesses lost access to water, McGuire said.

About 72,000 people lost power, he said.

The power outage involved the main transmission line that runs into the region and Pacific Gas & Electric’s restoration work was slowed because rain prevented use of a helicopter to assess damage, McGuire said. The utility expected electricity to be restored by evening, but residents should be prepared for more time without power, he said.

Humboldt County has about 136,000 residents and is in a part of the state that has a long history of large earthquakes, including a magnitude 7.0 in 1980 and a 6.8 in 2014, according to the California Earthquake Authority.

The city of Eureka, population 26,000, said on its website that “no significant damage” was immediately reported.

Eureka resident Dan Dixon, 40, said he and his wife were sleeping when it jolted them awake and shook everything, throwing pictures in their home to the ground. Their infant daughter, he said, slept through it.

“It was probably the most violent earthquake we have felt in the 15 years I have lived here,” he said. “It physically moved our bed.”

Caroline Titus, a resident of Ferndale, tweeted video in her darkened home of toppled furniture and smashed dishes.

“Our home is a 140-year-old Victorian. The north/south shaking is very evident in what fell,” she tweeted.

“That was a big one,” she said in another tweet.

Larkin O’Leary, 41, of Santa Rosa, traveled to spend her anniversary with her husband in Ferndale, where they had been jolted by an earthquake last year. They decided to try again and booked the romance package at a historic inn, the same spot as a year ago.

O’Leary said she woke at 2:30 a.m. with an eerie feeling and tried to go back to sleep.

“I laid back down again and it was almost as if someone jumped on the bed,” she said. “It was so terrifying.”

“It shook in a way I had never experienced. It was up, down, all around,” she said.

The couple quickly got out of Ferndale and returned to their home.

“Never again,” O’Leary said.

The earthquake occurred in an area known as the Mendocino Triple Junction, where three tectonic plates meet.

“We’re in this moment of geologic time where the most exciting, dynamic area of California happens to be Humboldt County and the adjacent offshore area,” said Lori Dengler, professor emeritus of geology at Cal Poly Humboldt.

Dengler said it is typical for there to be uncertainty about damage after a large earthquake. But she noted that much of the area is rural and wood frame construction is common, which in the past has helped limit damage.

The quake triggered the West Coast’s warning system that detects the start of a quake and sends alerts to cellphones in the affected region that can give people notice to take safety precautions before strong shaking reaches them.

About 270,000 people received notifications early Tuesday, said Ferguson, the Cal OES spokesperson.

The earthquake came just days after a small magnitude 3.6 earthquake struck the San Francisco Bay Area, waking up thousands of people before 4 a.m. Saturday and causing minor damage.

That earthquake was centered in El Cerrito, about a 16-mile (25-kilometer) drive to downtown San Francisco.

The Associated Press contributed to this report.