A powerful earthquake that struck the region north of San Francisco on Tuesday killed at least two Californians and injured 15 others.
According to the United States Geological Survey (USGS), the quake spread about 15 kilometers deep near the town of Eureka in Humboldt County.
The 6.4 magnitude tremor, which lasted about 20 seconds, caused houses to slide off their foundations, gas lines to rupture and walls to collapse.
Many streets in the district north of San Francisco became impassable and the power supply collapsed.
While the region was shaken by about 100 aftershocks on Tuesday, California Gov. Gavin Newsom declared a state of emergency to provide state and Washington recovery aid.
Meanwhile, geologists urged the population to stock up on food, water and flashlights.
The probability of another quake measuring 5.0 or greater in the coming week, the California Geological Survey said, is about 13 percent.