An earthquake with a preliminary magnitude of 5.8 struck near Washington, D.C. Tuesday afternoon, the U.S.Geological Survey said.
The epicenter was in Virginia.
The quake was felt in Philadelphia, Pennsylvania; New York City and on Martha's Vineyard where President Barack Obama is vacationing. Cell phone service has been disrupted in New York City where parts of Manhattan have been evacuated.
According to reports the Pentagon was evacuated.
"When the building began shaking rather violently, hundreds of people began streaming out," on reporter said, adding, "Everyone thought it was under attack."
It was unclear from early reports if only non-essential civilian personnel were ordered out of the building, or whether the evacuation was broader in implementation.
The Pentagon was dedicated as the headquarters of the US military on January 15, 1943 and is the largest low-rise office building in the world. Those who work within its walls often simply call it "The Building" or "Fort Fumble." The term "the Pentagon" is often used to refer directly to the Department of Defense, rather than the building itself.
The building houses approximately 23,000 US military and civilian employees, and about 3,000 non-defense support personnel in Arlington, Virginia, just outside Washington, D.C. It has five floors above ground (and two basement levels) - each floor has five ring corridors.
People reported feeling the ground move as far north as Boston and as far south as Anderson, S.C. A Columbus, Ohio, government worker reported the building shook there, as well.
In Washington, people spilled out onto the streets and reports came in that the earthquake was strong enough in Virginia to break glass and shake products off store shelves.