WASHINGTON (AP) — A seismic assessment of the Washington Monument has concluded that it's "extremely unlikely" another earthquake in the next two millennia will damage the monument any more than last year's 5.8-magnitude quake.

The National Park Service released the assessment on Thursday, a year after the quake that caused several large cracks to form in the top portion of the monument. The 555-foot-tall obelisk has been closed to the public ever since and is likely to remain closed for repairs until 2014.

A repair plan released last month said engineers had not recommended any further strengthening of the monument against future earthquakes. The seismic assessment bolsters that recommendation by pointing out that the monument shook more violently last year than during any earthquake that's likely to occur in the next 2,475 years.