An earthquake jolted San Francisco Bay area residents awake early Friday, breaking glass and rattling nerves, although there were no immediate reports of injuries.
The earthquake was recorded about 2 miles (3 kilometers) east of Oakland and had a preliminary magnitude of 4.2, according to the U.S. Geological Survey. It could be felt for up to 10 seconds on both sides of the California's San Francisco Bay after striking shortly after 4:40 a.m. (1140 GMT).
Residents east of San Francisco were shaken awake as pictures slipped from walls and objects tumbled.
Some businesses delayed opening because of broken windows, and Pacific Gas and Electric Co. reported that some customers in Oakland briefly lost power.
A dispatcher at the Oakland Police Department said police were getting calls about alarms going off. In Berkeley, an employee at a grocery store said two large windows broke but there were no injuries.