the Gulf coast. The Corps worked with the U.S. Coast Guard, Army National Guard and other state and federal authorities to bring in all assets available to expedite the process. "We're attempting to contract for materials, such as rock, super sand bags, cranes, etc., and also for modes of transportation like barges and helicopters, to close the gap and stop the flow of water from Lake Pontchartrain into the city," said Walter Baumy, Engineering Division chief and project manager for closing the breach. Flooding Corps' engineers initially believed that water in the 17th Street Canal overtopped the floodwall, scoured behind the wall, and caused it to collapse. However, three local fire captains confirmed with video footage that the floodwall had failed before water reached the top. The floodwall breached on the lower (New Orleans West End) side inland from the Old Hammond Highway Bridge. There were three major breaches at the Industrial Canal; one on the upper side near the junction with MR-GO, and two on the lower side along the Lower Ninth Ward, between Florida Avenue and Claiborne Avenue. The London Avenue Canal breached in two places, on the upper side just back from Robert E. Lee Boulevard, and on the lower side a block in from the Mirabeau Avenue Bridge. By the evening of August 29, 2005, approximately 28 levee failures were reported throughout the city. Approximately 66% to 75% of the city was now under water. Wind and other storm damage had already stopped the city. Many power lines were down and the remains of trees and buildings blocked streets. As Corps of Engineers' workers began working with the Federal Emergency Management Agency (FEMA) begin work on city cleanup and civil engineering tasks, several boats surveyed the flooded areas and blocked waterways around the city. Corps of Engineers used crane barges to remove barges that had been washed atop bridges and other structures. Plans were made to begin levee work, including the placement of 3,000 pound sand bags on the 17 Street Canal. Army National Guard helicopters began assisting in this operation August 31. Meanwhile, Lake Pontchartrain started slowly draining and was expected to return to normal levels in about 36 hours. Recovery The breach at the 17th Street Canal Levee, a levee-floodwall combination, was found to be about 300 feet (100 m) long. The Corps began operating on an initial hypothesis that the force of the