Millions of people were told to prepare for a tsunami after a 7.0 magnitude earthquake struck off the coast of northern California.
Officials raised the alarm after the quake struck at 10.44am local time (6.44pm) around 39 miles southwest of Ferndale, near the Oregon border, according to the US Geological Survey (USGS).
The tsunami warning covered a large stretch of the California and Oregon coasts populated by around 4.7 million people – but was eventually lifted around an hour after it was issued.
It had initially been predicted by the National Weather Service that a wave could reach the San Francisco area as early as 12.10pm local time.
Rachel Kennedy, a meteorologist with the service, called it a “pretty dangerous situation”.
Meanwhile, the San Francisco Zoo was evacuated while staff made sure all its animals were secured.
However, the tsunami warning was cancelled after computer analysis and other monitoring equipment established that the quake was unlikely to cause large waves.
There were also no immediate reports of any serious injuries or significant damage following the earthquake.
Nonetheless, it was felt widely across northern California and as far south as San Francisco, where residents felt a rolling motion for several seconds. It was followed by smaller aftershocks.
In the Santa Cruz area, phones buzzed with a tsunami warning from the National Weather Service that said: “A series of powerful waves and strong currents may impact coasts near you. You are in danger.
“Get away from coastal waters. Move to high ground or inland now. Keep away from the coast until local officials say it is safe to return.”
More than 1.3 million people lived close enough to the quake that they could have felt it, the USGS estimated.
The San Francisco Bay Area Rapid Transit District, known as BART, stopped traffic in all directions through the underwater tunnel between San Francisco and Oakland.
Julie Kreitzer, owner of food and souvenir shop Golden Gait Mercantile in Ferndale, said: “It was a strong quake, our building shook, we’re fine but I have a mess to clean up right now.”
She added: “We lost a lot of stuff. It’s probably worse than two years ago. I have to go, I have to try and salvage something for the holidays because it’s going to be a tough year.
“The kids were so great and terrified. It seemed to go back and forth for quite a long time.”
Eureka mayor Kim Bergel said evacuations were in place for people to move to higher ground in areas of the city under the tsunami warning and crews were assessing damage from the quake.
Ms Bergel, who works as a resource aid at a middle school, said lights swayed as everyone got under desks to shelter.
California governor Gavin Newsom met with state emergency officials shortly after the quake.