Tens of thousands of homes and businesses lost power as a preliminary magnitude 6.4 earthquake shook Northern California early on Tuesday morning, startling locals and damaging infrastructure.

According to officials, the earthquake that damaged buildings and roads near Humboldt County, about 250 miles north of San Francisco, resulted in at least two injuries.

According to the U.S. Geological Survey, the earthquake occurred at 2:34 a.m. PT in Pacific Ocean waters just over 16 miles beneath the surface, 7.5 miles west of Ferndale. Near the state line separating California and Oregon, the city is located about 19 miles south of Eureka.

In the wake of the 6.4 magnitude earthquake, the USGS predicted “many” aftershock earthquakes, some of which could be as strong as 4. On the USGS website, more than twenty aftershocks were noted, the majority of which were smaller than magnitude 4.

The earthquake, which was the strongest in the region in years, was not associated with a tsunami threat as of early Tuesday morning, according to the National Weather Service’s tsunami warning system.

“Check for damage or leaks in the water and gas lines. Take care when you’re traveling, “Just after 6:30 a.m. PT, the Humboldt County Office of Emergency Services tweeted.

The county, which has a population of about 136,000, has received reports of damage to homes and roads, according to the Humboldt County Sheriff’s Office.

Sheriff’s information specialist Samantha Karges confirmed two injuries to USA TODAY. According to Karges, numerous additional injuries have been reported but have not yet been verified.

Officials also reported at least two entrapment-related structure collapses where rescuers managed to free trapped victims. These incidents’ specifics were not immediately known.

The confirmed victims’ recoveries were anticipated, according to Karges.

According to Karges, the majority of the destruction occurred in Rio Dell, Fortuna, and Scotia in the Eel River Valley, in addition to Ferndale.

Tens of thousands of customers were still without power in the area as of around 9 a.m. PT, according to Pacific Gas & Electric Co. More than 71,000 residents of Ferndale’s home county of Humboldt were without power.

Some gas leaks were also reported.

Diana McIntosh, 69, said the trembler woke her up inside her home in an apartment complex in central Humboldt County.

State Route 211, which connects Ferndale with U.S. 101, was seen in a photo posted online by the California Department of Transportation toppling due to the earthquake. According to the Ferndale Fire Department, other nearby roads were also closed because of damage, including Blue Slide Road, which is located next to U.S. 101, a significant north-south route that connects Los Angeles to Washington state.

According to the state Department of Conservation, Tuesday’s 6.4-magnitude earthquake may be the most significant to occur in California since a 7.1-magnitude earthquake struck the Ridgecrest region of Southern California in July 2019. In 2016, a 6.5-magnitude earthquake near Ferndale was recorded about 100 miles offshore.

Additionally, it follows an earthquake of magnitude 5.1 that shook the San Francisco Bay Area in late October. The natural disaster did not cause any injuries. The Calaveras Fault, one of eight significant faults in the Bay Area and a branch of the San Andreas Fault line, is where the earthquake occurred.

According to USGS data, the early-morning earthquake on Tuesday was the biggest the region had seen in years. The most recent significant earthquake was a 6.2-magnitude one that occurred offshore in Northern California’s Cape Mendocino region in December 2021.

The epicenter of that earthquake was located just off the coast, about 210 miles northwest of San Francisco, close to the small town of Petrolia, which has a population of less than 1,000.

A 9.2 magnitude earthquake that struck Alaska’s Prince William Sound region on March 27, 1964, was the largest earthquake in recorded history.

The epicenter of the earthquake, which was about 6 miles east of the mouth of College Fiord and 75 miles east of Anchorage, was located approximately 15.5 miles beneath the earth’s surface, according to the USGS.

The quake, which lasted for about 4.5 minutes, was the strongest ever recorded in the United States. In addition, after the magnitude 9.5 earthquake in Chile in 1960, it is the second largest earthquake ever to be recorded.