since the 1980s. what happened during the course of the storm normal output pipes jammed. you had a tremendous amount of water going into the reservoir. the spillway functioned as it should but hadn't handled this volume of water up to this point. >> the volume of water came through so fast and the spillway had some structural issues and it ripped out the bottom half of the spillway. it is starting to erode back to the bottom of the dam. >> the foundation is sand. if it erodes all the way up to the dam you could talk about a failure of the dam which would flood hundreds of families that live below the dam. what you have happening on the ground, u.s. marines are looking up jersey barriers to cables. navy pilots come in with helicopters and they hook the barriers to the helicopter and the helicopter pilots drop these at the foot of that spillway. in theory what they're trying to do is build a big pile of