Aug. 24, 2011— -- The strongest earthquake to hit the East Coast of the U.S. in seven decades damaged landmark buildings in the Washington, D.C. area, while rattling the nerves of tens of millions, just three weeks ahead of the 10th anniversary of the September 11 attacks.
Though there are no known deaths after the quake that struck at 1:58 p.m. Tuesday, damage overall was estimated at $100 million.
The National Park Service discovered cracking in the stones at the top of the Washington Monument, which will be closed indefinitely, according to the Associated Press. While inspecting it via helicopter the NPS noticed a crack in what they refer to as the paramedian – at the very top of the triangle.
At the historic National Cathedral in Washington, D.C. damage has been confirmed to three of four pinnacles atop the tower, while reports indicated cracks appeared in the flying buttresses around the east end of the cathedral.
SEE PHOTOS: Earthquake Rocks East Coast Cities
Experts are working to assess the building damage, both structurally and aesthetically, according to a statement on the monument's official website.
Elsewhere in the capital, the largest metropolitan area close to the quake's epicenter, the Cross family from Michigan was at the top of the Washington Monument when the quake struck. They said that they felt the 555 foot monument sway nearly a foot, and said they felt pieces of the monument falling on them.
The White House and Capitol building were evacuated following the quake, and the Park Service closed all monuments and memorials on the National Mall. The Capitol was reopened by late afternoon for people to retrieve their things, according to the Associated Press.
In Louisa County, Va. -- the epicenter of the earthquake -- 911 dispatchers reported a massive spike in calls with some terrified residents phoning in to verify what had happened and seek consolation.