"Everything started trembling, with a big boom sound coming up from the ground. I've lived in L.A. long enough to know this drill, so rushed upstairs, and found the glassware still shuttering for about a minute. Couldn't get through by the phone to friends, and there was no news online, so I started worrying my house was collapsing," Lewenz said.
Since there were no serious injuries, some saw the lighter side in the unexpected quake.
Michelle Mittelstadt said, "My first earthquake! What's next: Plague of locusts?"
Another woman who works with the Federal Aviation Administration said, "If you have to be evacuated for an earthquake, the National Mall is a nice spilling-out point!"
The earthquake felt along the eastern corridor follows an earthquake felt Monday in Colorado. That 5.3 magnitude earthquake struck near Trinidad, Colo. The USGS's Wald said he saw "no evidence" the two were related physically; they were simply "coincident in time."
The United States' Geological Survey said that earthquakes have been felt in the central Virginia area since 1774.
ABC News' Jane E. Allen, Christina Caron, Troy McMullen, Jack Cloherty, Jim Sciutto, Aaron Katersky and Dennis Powell contributed to this report.