EL CERRITO (CBS 5 / KCBS) -- An earthquake with a magnitude of 4.0 shook the Bay Area at 5:33 a.m. on Monday.
The shallow quake was centered a mile north of El Cerrito, two miles from Richmond, four miles north of Berkeley and 13 miles from San Francisco City Hall.
An initial report placed the magnitude at 4.3. The U.S. Geological Survey subsequently downgraded it to 4.0.
Phone-in and e-mail reports from viewers and listeners to KPIX-TV CBS 5 and KCBS All News 740 AM &FM 106.9 indicated that the quake was felt across much of the East Bay as well as the North Bay and San Francisco. The jerky tremor lasted only a few seconds.
One Twitter user wrote, "All of San Francisco just woke up, tweeted, and are now going back to bed for an hour. Thanks early morning #earthquake."
There were no initial reports of damage or injuries, and Pacific Gas & Electric Co. said there were no power outages caused by the quake.
Bay Area Rapid Transit did briefly halt service during the early morning commute to conduct track inspections. Inspections of the iconic Golden Gate Bridge also found no damage.
KCBS' Holly Quan Reports:
The tremor was felt by bridge staff as a "quick jolt," said Golden Gate spokeswoman Mary Currie.
The USGS indicated some aftershocks had occurred, most notably a magnitude 2.0 around 6 a.m. near East Richmond Heights, which is about a mile from the epicenter of the 4.0 quake.
Bay Area Rapid Transit trains were briefly delayed after the quake to inspect the tracks.
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