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.
A number of small aftershocks are likely, says Dale Grant, a geophysicist with the U.S. Geological Survey. "We would not expect anything bigger, but it cannot be completely ruled out.
"The earth does what it does," he added.
The quake was felt as far north as New Hampshire and in Martha's Vineyard where President Obama and his family are vacationing. It was felt as far south as South Carolina and as far west as Cleveland, Ohio.
Over the last 10 years, earthquakes have been felt in every state, said geophysicists at the U.S. Geological Survey at a press conference late this afternoon. Today's quake was felt in 25, an event David Wald called "rather unique."
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The East Coast gets earthquakes from time to time, but rarely of a magnitude to make skyscrapers sway.
Paul Segall, a Stanford geophysicist who studies the structure and development of earthquake faults, called today's shaker "a significant earthquake for that part of the world. It could do significant damage."
"I can't remember an event that large on the East Coast," he said.
No significant damage or fatalities have been reported. Some injuries have been reported in Washington D.C., the fire department spokesman told the Associated Press. In New York City, the fire department said that they received a surge in calls.
Authorities in New York and Washington said cell phone traffic was so heavy that it hampered their ability to respond to emergencies. A spokesperson for the Federal Emergency Management Agency urged people to email and use text messaging instead of their cell phones for their next few hours to ease the congestion.
The epicenter of the quake was near Mineral, Va., 39 miles from Richmond, Va., and 83 miles from the nation's capital. The quake was .6 miles deep.