Washington ( CNN ) -- Just days after a magnitude 5.8 earthquake cracked the Washington Monument in four places , the National Park Service is trying to protect it from being further damaged by Hurricane Irene , spokeswoman Carol Johnson said Friday . Engineers for the National Park Service are working inside the Washington Monument to `` plug holes and catch anything that they ca n't plug , '' Johnson told CNN . `` We have a group of people who are on ropes up there , trying to pin and plug whatever they can . '' The engineers are using a flexible insulation called backer rod . `` They are basically jamming it into the cracks , '' Johnson said . `` They are doing what they can and putting this backer rod in and then they are going to go back up and inspect after the storm , '' she added . One area of special concern -- the most extensive damage to the stonework near the top caused by Tuesday 's earthquake . `` The crack is about 4 feet long and 1 inch wide and in some places wider and you can see sunlight through the crack , '' Johnson said . The monument is closed indefinitely to the public while engineers assess the damage caused by the quake . Even without the new cracks , the monument would have experienced seepage because of the way it was built , according to Johnson . `` The anticipation is there will be more water because of these cracks . These cracks allow the water to get directly through and that is why we are doing everything we can to put in temporary waterproofing , '' Johnson said . However , the water is not expected to compromise the stability of the structure , she said . The first rain bands from Hurricane Irene began hitting the South and North Carolina coasts Friday . The storm is expected to near the D.C. area Saturday night into Sunday .
Park service engineers are using flexible materials to fix cracks caused by quake . The park is closed indefinitely while engineers assess the damage . Hurricane Irene is threatening much of the East Coast , from the Carolinas to New Jersey .