Update - 8:43 p.m. -- Hours after a 5.8 magnitude earthquake shook Northern Virginia, an aftershock measuring 4.2 on the Richter scale struck the area again, according to the United States Geological Survey.
This aftershock, which occurred around 8:04 p.m., according to USGS, was the third recorded today. The first measured 2.8 at 2:46 p.m., followed by another measuring 2.2 at 3:20 p.m.
All three aftershocks, as well as the initial earthquake, occurred near Mineral, Va., about 35 miles northwest of Richmond and 84 miles southwest of Washington, D.C.
The first two aftershocks were measured to be less than one mile underground; the third was about 4.8 miles underground, USGS data says.
Dozens of patrons at the Panera in West Springfield hid under tables when shaking rocked the building at about 1:51 p.m.
The U.S. Geological Survey confirmed a 5.8 magnitude earthquake started in Mineral, Va. and has been felt as far north as Boston and beyond, and as far south as Atlanta.
"I felt the floor shaking, then I heard a crack and I thought the ceiling was going to come down," said Erin Gilbert, a teacher eating in the Panera in West Springfield.
"I felt the floor rumbling like the Metro was going underneath and I said, 'Get under the table!'" said Erin's friend, Sue.
So far, there are only limited infrastructure damages in Fairfax County, according to Fairfax County officials.
However, voters who were heading to the polls today for the Virginia primary elections while experts check buildings for any structural damage or loose building materials. In Alexandria City, at one location while poll workers evacuated.
All Ft. Belvoir buuildings were evacuated. "We felt a big bump," said Col. Mark Moffatt, deputy garrison commander. "The response at military installations like this is to clear the buildings until we figure out what the issue is."
"Was that my car? I thought it was my car. I didn't think they had earthquakes in Virginia, said Lily Thompson at Ft. Belvoir.
"I've lived in California through many earthquakes, and I never ever thought there would be one in Virginia," said Jen Thompson, a Gainesville resident at the .
Customers at the West Springfield Panera immediately grabbed their cell phones, but couldn't get service. According to twitter reports, cell phone service was largely out in the area for about an hour, though many people were able to send text messages.
Federal employees were sent home early, and heavy traffic was reported along I-66, the Beltway and in downtown Washington.
Virginia Department of Transportation (VDOT) crews are checking Virginia bridges. They ask drivers to report any road infrastructure problems to 1-800-FOR-ROAD.
Minor Damage at Some Schools
At 4 p.m., Fairfax County Public Schools said they'd received reports of earthquake damage at some schools. In an email, FCPS media specialist Mary Shaw said those schools will be inspected today. "If this assessment determines that a more extensive structural damage assessment is needed, those buildings will be closed until that is completed," she wrote. All schools will be inspected this week.
What To Do
Fairfax County provided these tips for safety during an earthquake. Aftershocks are normal. Two aftershocks were reported—one at about 2:45 p.m. and another one around 4 p.m. Fairfax County residents were not able to feel either aftershock.
Here are FEMA's guidelines for what to do after an earthquake.
After any natural event, fly-by-night operators may come into affected areas, looking to make a quick buck off of residents who aren't educated about consumer protections. The Commonwealth of Virginia has a consumer protection division that will investigate these things. More information on protecting yourself from scammers after a disaster is available online from the Virginia Dept. of Agriculture and Consumer Services.