A huge 6.4-magnitude tremor has battered California this morning, with locals saying it's the 'most intense they have ever felt'.
The US Geological Survey confirmed the quake hit at a depth of 10 miles at 2.34am near Eureka, in California's Humboldt County.
The recorded depth indicates the tremors were from a shallow earthquake, which is felt more strongly because it was closer to the surface.
Images and footage shared on social media showed the extent of the damage this morning.
The historic Fernbridge in Ferndale, CA was left with four gaping cracks on it after being ripped apart by the tremors. The bridge has been rocked by several quakes since it was built in the early 1900s, including in 1992 when it withstood one exceeding 7.0 in magnitude.
Glass shatter covered the pavement in other areas after windows were blown out of shops in Fortuna, while at least 66,000 Californians were left without power.
Former publisher of the The Ferndale Enterprise, Caroline Titus, shared a video showing a home in ruins with personal affects scattered all over the floor after this morning's rumbling.
She wrote: "That was a big one. Power is now out in [Ferndale]. House is a mess.
"Our home is a 140-year-old Victorian. The north/south shaking is very evident in what fell. This was our coffee station. Sorry for dark video. Power still out."
Another resident, in Chico, described it as having a "rolling feeling".
Humboldt County reported widespread damage across the area, urged caution while travelling, and said locals should be "prepared for aftershocks".
Officials wrote on Twitter: "This is a Humboldt Alert. Due to a large earthquake, widespread damages to roads and homes are reported throughout Humboldt County. Be prepared for aftershocks. Check gas and water lines for damages or leaks. Exercise caution if traveling."
Meanwhil,e Fortuna and the town of Rio Dell have reported gas leaks after a building collapsed, according to the local fire service.
No casualties have been reported as of the time of writing, but it's believed one person may be unaccounted for in Rio Dell.
According to earthquake analysts at Volcano Discovery, the seismic activity should have been felt by everyone at its epicentre.
Dangerous ground shaking has the potential to "inflict moderate to heavy damage to buildings and other infrastructure", the site adds.
Officials haven't issued a tsunami warning, but emergency earthquake alerts were issued by USGS.
Their message read: "Earthquake Detected! Drop, Cover, Hold On. Protect Yourself."
California is a leader in earthquake alert systems, having created a way to notify users on their phones just moments before the earth begins to shake.
Thanks to some useful technology developed at the University of California Berkeley, many of those who experienced the 5.1 magnitude earthquake in the Bay Area of California in October were warned before it struck.
Messages estimating the magnitude and a person's distance from the epicentre appeared on phones mere moments before the quake occurred, giving people the ominous warning to "expect shaking".
Around 90,000 people near the city of San Jose were told of the incoming quake somewhere between two and 18 seconds before.
In December last year, a tremor similar to today's struck the same area, registering 6.2 on the Richter scale.
The quake took place 24 miles west of Petrolia at a depth of 9 km (5.6 miles), according to the European Mediterranean Seismological Centre.
The quake was so powerful it smashed the windows of buildings along the coast.
Americans in the area described it as a 'big one'.
