An unusually strong magnitude 5.8 earthquake struck central Virginia Tuesday afternoon, sending tremors along the East Coast and prompting office buildings from Washington D.C. to New York to be evacuated. There were no immediate reports of injury or serious structural damage.The earthquake struck near Mineral, Va., more than three miles below sea level, the U.S. Geological Survey said. Mineral is town 83 miles from D.C. and has been known for its seismic activity, but seldom produces a substantial earthquake.Most of downtown D.C. was evacuated, including the U.S. Capitol, the Pentagon and other office buildings. Pictures on the wall in the Capitol building reportedly fell and panicked workers ran to the exits, apparently fearing a 9/11-style attack. Workers were told not to re-enter the buildings.Marine helicopters were seen hovering above the D.C, and there were reports that the Washington Monument may be tilting.