Washington (CNN) -- The Washington Monument remains "structurally sound" and is "not going anywhere," a top National Park Service official said Monday, announcing the result of a comprehensive assessment of the structure's interior.
A five-day examination of the monument's exterior will begin Tuesday, according to Bob Vogel, superintendent of the National Mall and Memorial Parks.
Four cracks in the monument's marble were discovered shortly after a 5.8-magnitude earthquake struck the East Coast on August 23. The monument has since been closed to the public.
Officials declined to say Monday when the monument will re-open.
Small pools of standing water were found in the monument during inspections following Hurricane Irene, the National Park Service said in late August.
"What happened was a lot of mortar popped out, so much so that you can see sunlight above 450 feet in the monument," spokeswoman Carol Johnson said at the time.
The National Park Service has been working with an engineering firm to determine the extent of the damage and what it will cost to fix it. Repairs will include pinning several stones together and replacing some mortar, Johnson noted.
The Washington Monument, built between 1848 and 1884, is 555 feet, 5 and one-eighth inches tall. Its walls are 15 feet thick at the base and 18 inches at the top, and are composed primarily of white marble blocks, according to the National Park Service.