Dave Megerle, a member of engineering firm Wiss, Janney, Elstner, Associates "Difficult Access Team," attaches ropes to the top of the Washington Monument, on the National Mall, in Washington, Tuesday, Sept. 27, 2011, from which four people will rappel down the sides to survey the extent of damage sustained to the monument from the August 23 earthquake which shook much of the East Coast. According to the Park Service, the heaviest damage appears to be concentrated at the very top of the monument, in what is called the pyramidion, where large cracks of up to 1-1/4 inch wide developed through stone and mortar joints. The Washington Monument, built between 1848 and 1884, is 555 feet, 5-1/8 inches tall. Its walls, 15-feet thick at the base and 18-inches at the top, are composed primarily of white marble blocks. (Photo by Jeff Malet)

Dave Megerle, a member of engineering firm Wiss, Janney, Elstner, Associates "Difficult Access Team," attaches ropes to the top of the Washington Monument, on the National Mall, in Washington, Tuesday, Sept. 27, 2011, from which four people will rappel down the sides to survey the extent of damage sustained to the monument from the August 23 earthquake which shook much of the East Coast. According to the Park Service, the heaviest damage appears to be concentrated at the very top of the monument, in what is called the pyramidion, where large cracks of up to 1-1/4 inch wide developed through stone and mortar joints. The Washington Monument, built between 1848 and 1884, is 555 feet, 5-1/8 inches tall. Its walls, 15-feet thick at the base and 18-inches at the top, are composed primarily of white marble blocks. (Photo by Jeff Malet)