Two people have died and tens of thousands of households were left without power after a magnitude 6.4 earthquake rocked northern California.

The tremor, 215 miles (350km) north of San Francisco, has caused widespread damage to roadways.

"Anything that was on the walls broke off the walls," said JB Mathers, a resident of the coastal city of Eureka.

Authorities have closed several roads and warned the public to brace for aftershocks.

Scientists have been saying for decades a good part of California is living on borrowed time, and could slide into the sea at any moment. Everyone is waiting for the Big One.

I lived south of San Francisco for a while. A beautiful area  with great weather most of the year. But I never got used to the feeling that an earthquake could strike at any time. There were many tiny earthquakes. Then you could hear things in the cupboard or on the wall shaking.

 

The "funny" thing was years after I left California, I experienced a major earthquake in the Philippines. I was using my notebook when it happened. I immediately turned it off to protect the hard drive and ran with it into the smallest room - the bathroom. And the worst thing was that you had to wait for aftershocks afterwards.