Magnitude-5.6 earthquake shakes Northern California, injures several and damages homes

A magnitude-5.6 earthquake rattled rural Northern California near Redwood Valley in Mendocino County at 8:10 a.m. Wednesday, injuring several people, knocking items off shelves and forcing officials to check buildings, utilities and warning systems across the region. The U.S. Geological Survey placed the epicenter about 11 kilometers north of Redwood Valley and said the quake struck 8.9 kilometers below the surface.

The U.S. Geological Survey estimated that about 80,000 people experienced moderate to very strong shaking, while roughly 10 million felt weak to light shaking across a broader swath of the state. The agency activated ShakeAlert, sending push notifications to residents across Northern California, including some in Sacramento who received warnings even though they did not feel strong shaking. Gov. Gavin Newsom said he had been briefed. More than 1 million Californians received the alert.

No deaths were reported, but officials said several people were hurt and damage assessments were still underway in Mendocino County and surrounding communities. Pacific Gas and Electric Co. said about 8,000 customers were affected by outages near the epicenter and that it activated its emergency response plan for gas and electric hazards. Pacific Gas and Electric Co. had not identified damage to its equipment.

The National Tsunami Warning Center issued no tsunami warning, advisory, watch or threat. The U.S. Geological Survey said the event was likely the mainshock in an earthquake sequence, with a 77% chance of at least one magnitude 3 or greater aftershock in the next week. Three smaller quakes, each below magnitude 2.7, followed near the epicenter within an hour.

In Redwood Valley, the earthquake sent merchandise tumbling at the Redwood Valley Market. In Ukiah, the Mendocino County Superior Courthouse briefly evacuated and paused proceedings until county maintenance could inspect the building.

The quake was the strongest earthquake in that rural part of Northern California since 1940.