Another earthquake rattled the East Bay tonight.
The 3.8 quake hit at 8:16 p.m. and was centered 1 mile east of Berkeley.
"It felt like a giant picked up our apartment building and threw it down," said Katherine Erickson, an Oakland resident who lives near the epicenter.
This evening's quake follows a 4.0 magnitude earthquake that shook the East Bay this afternoon.
That quake hit at 2:41 p.m. It was centered 2 miles southeast of Berkeley, according to the U.S. Geological Survey.
An aftershock in the same epicenter was reported at 4:50 p.m. It measured 2.2.
The first quake was felt in Berkeley, Oakland, San Francisco, Union City, Newark, San Leandro, Lafayette and the San Ramon Valley, among other places.
There were no reports of serious damage or injury. However, BART delayed trains up to 15 minutes systemwide this afternoon to conduct safety checks. They said they will be similar delays tonight.
Berkeley police said they have not received any reports of damage or injuries but have gotten some calls about car and building alarms that were activated by the quake.
Keith Knudsen, deputy director of the USGS Earthquake Science Center in Menlo Park, said today's temblor was a standard Hayward Fault Line quake.
He said the temblor was of the typical "strike-slip" variety, in which two sides of the fault slide horizontally.
Knudsen said the USGS had not yet recorded any aftershocks and that there is a roughly 5 percent chance that this afternoon's quake could be a foreshock to a larger seismic event.
Mother Nature certainly has good timing. Today many around the Bay joined an estimated 8 million Californians who participated in .
Students and faculty at the University of California at Berkeley also participated in the drill called ShakeOut, sounding a siren across campus this morning, school spokeswoman Janet Gilmore said.
If you'd like to share what you felt with the USGS, click here to fill out their Did You Feel It? form.
— Bay City News contributed to this report.