On Tuesday, August 23, 2011, a 5.8 magnitude earthquake, occurred 84 miles southwest of Washington, D.C., damaging the Washington Monument. The National Park Service has temporarily closed the Monument and is assessing the damage to it.

The earthquake that caused significant structural damage to the Washington Monument occurred on August 23, 2011, and had a magnitude of 5.8. Known as the Virginia Earthquake, its epicenter was near Mineral, Virginia, about 90 miles southwest of D.C. While a 5.8 might seem moderate compared to West Coast quakes, the dense, old rock of the East Coast allowed the seismic waves to travel much further and with more intensity than a similar quake would have in California. The monument, being the world's tallest unreinforced stone masonry structure, was particularly vulnerable. It suffered over 150 cracks, including several large vertical fissures near the top (the pyramidion) and significant mortar loss. The damage was so severe that the monument remained closed for nearly three years for a $15 million repair project. This included the use of specialized "difficult access" teams who repelled down the exterior to hand-repair the stones with lime-based mortar, ensuring the historic obelisk was stabilized against future tremors.