Earthquake swarm strikes La Habra area, felt in five counties - Seismologists have yet to assign a particular fault

LA HABRA - A magnitude-5.1 earthquake struck at 9:09 p.m. tonight, centered one mile east of La Habra, the U.S. Geological Survey reported, causing some water main breaks in Fullerton, but little significant damage.

The earthquake was felt in at least seven Southern California counties -- Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego and Ventura.

The quake was at a depth of around one mile and followed by about 20 aftershocks, two greater than magnitude 3.0, Caltech seismologist Robert Graves. There were no reports of surface rupture and scientists are not yet able to assign...