Earthquake Rocks Northern California, US

An earthquake with a magnitude of 6.0 has shaken northern California,
reports the US Geological Survey.

The USGS said it struck at 03:20 local time (10:20 GMT) four miles
(6km) north-west of American Canyon, at a depth of 6.7 miles.

The site is 51 miles from Sacramento and about 30 miles north-east of
San Francisco, where many Twitter users say it woke them up.

There were no immediate reports of injuries or serious damage.

More than 10,000 households were without power in Napa County, about
six miles from the earthquake's epicentre, and the surrounding area,
the Pacific Gas and Electric Company said.

The California Highway Patrol in the San Francisco Bay Area tweeted
that it was "checking over crossings and bridges for obvious signs of
structural integrity" and asked residents to report any signs of
problems.

Twitter users in the quake zone contacted the BBC to share their experiences.

Sarah McLellan tweeted: "On 6th floor entire building swaying,
shaking", while Matt Dyar said: "Major shaker. Stuff off shelfs.
Broken glass. No house damage that is obvious."

Another Twitter user said: "I haven't felt one that big since the
Northridge quake in the early 90s."

California lies on the San Andreas Fault, which forms the tectonic
boundary between the Pacific Plate and the North American Plate, two
of the large moving plates that form the Earth's crust.

The San Francisco earthquake of 1906 and subsequent fires devastated the city.

In 1989, a powerful earthquake struck San Francisco, killing nine
people and injuring hundreds.