WASHINGTON (AP) — A 5.9 magnitude earthquake centered in Virginia forced evacuations of all the monuments on the National Mall in Washington and rattled nerves from Georgia to Martha’s Vineyard, the Massachusetts island where President Barack Obama is vacationing. No injuries were immediately reported.

The U.S. Geological Survey said the earthquake was half a mile deep and centered near Louisa, Va., about 40 miles northwest of Richmond. Shaking was felt at the White House and all over the East Coast, as far south as Chapel Hill, N.C. Parts of the Pentagon, White House and Capitol were evacuated.

Two nuclear reactors at the North Anna Power Station in the same county as the epicenter were automatically taken off line by safety systems around the time of the earthquake, said Roger Hannah, a spokesman for the U.S. Nuclear Regulatory Commission.

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The Dominion-operated power plant is being run off of four emergency diesel generators, which are supplying power for critical safety equipment. Hannah said the agency was not immediately aware of any damage at nuclear power plants in the Southeast.

Obama and many of the nation’s leaders were out of town on August vacation when the quake struck at 1:51 p.m. EDT. The shaking was felt on the Martha’s Vineyard golf course as Obama was just starting a round.

At the Pentagon in northern Virginia, a low rumbling built and built to the point that the building was shaking. People ran into the corridors of the government’s biggest building and as the shaking continued there were shouts of “Evacuate! Evacuate!”

The U.S. Park Service evacuated and closed all National Mall monuments and memorials. At Reagan National Airport outside Washington, ceiling tiles fell during a few seconds of shaking. Authorities announced it was an earthquake and all flights were put on hold.

In New York, the 26-story federal courthouse in lower Manhattan began swaying and hundreds of people were seen leaving the building. Court officers weren’t letting people back in.

The quake came a day after an earthquake in Colorado toppled groceries off shelves and caused minor damage to homes in the southern part of the state and in northern New Mexico. No injuries were reported as aftershocks continued Tuesday.

In Charleston, W.Va., hundreds of workers left the state Capitol building and employees at other downtown office buildings were asked to leave temporarily.

“The whole building shook,” said Jennifer Bundy, a spokeswoman for the state Supreme Court. “You could feel two different shakes. Everybody just kind of came out on their own.”

In Ohio, where office buildings swayed in Columbus and Cincinnati and the press box at the Cleveland Indians’ Progressive Field shook. At least one building near the Statehouse was evacuated in downtown Columbus.

In downtown Baltimore, the quake sent office workers into the streets, where lamp posts swayed slightly as they called family and friends to check in.

Social media site Twitter lit up with reports of the earthquake from people using the site up and down the U.S. eastern seaboard.

“People pouring out of buildings and onto the sidewalks and Into Farragut Park in downtown DC…,” tweeted Republican strategist Kevin Madden.

“did you feel earthquake in ny? It started in richmond va!” tweeted Arianna Huffington, president and editor-in-chief of the Huffington Post Media Group.

John Gurlach, air traffic controller at the Morgantown Municipal Airport was in a 40-foot-tall tower when the earth trembled.

“There were two of us looking at each other saying, ‘What’s that?’” he said, even as a commuter plane was landing. “It was noticeably shaking. It felt like a B-52 unloading.”

Immediately, the phone rang from the nearest airport in Clarksburg, and a computer began spitting out green strips of paper — alerts from other airports in New York and Washington issuing ground stops “due to earthquake.”

Copyright 2011 The Associated Press.