The largest East Coast quake in memory rattled nerves and buildings from Martha's Vineyard to to North Carolina, prompted the evacuation of Congressional buildings, slowed rail and air traffic, and forced two nuclear reactors offline.
The earthquake, estimated to be a 5.8 magnitude, sent people pouring out of office buildings, hospitals, the Pentagon and the State Department when it struck at 1:51 p.m. The pillars of the capitol in Washington, D.C. shook. Alarms sounded in the FBI and Department of Justice buildings, and some flooding was reported on an upper floor of the Pentagon as a result of the quake.
Parks and sidewalks in Washington were packed with people who fled their buildings. All of the monuments along the National Mall have been closed. Police on horseback kept people a safe distance from the Washington Monument and the new Martin Luther King, Jr. Memorial.
National Parks Service Spokesman Jeffrey Olson told the Associated Press that there was "absolutely no damage" to the Washington Monument, Lincoln Memorial or other tourist destinations along the Mall.
The National Cathedral suffered damage to at least three of the cathedral's pinnacles, Dean of the Cathedral Samuel Lloyd said. The cathedral has been cordoned off with yellow police tape as a precaution.
Officials inspected Congressional buildings before members of Congress and their staff were allowed to return to their offices.
Read the ABCNews.com story here.