in three to four days. Several private firms have volunteered services and provided assistance in design of the closure. Similar work was planned for sealing a London Avenue breach, although in that case materials would come from demolition of Lakeshore Drive. Five pumps were ordered to assist in draining the city. The 17th Street Canal Levee, was now estimated to have a breach 450 feet (150 m) long. It was still believed that water overtopped the floodwall, scoured the structure, and then moved the structure 20 feet (6 m) horizontally. Work continued on nearby waterways, including several locks which were closed. Use of some of the locks required raising bridges. The Industrial Canal Lock needed repair, and its lockmaster raised the St. Claude Avenue bridge, but lowered it because of hostility from civilians wanting to cross on both sides. Water flow stopped By September 1, 2005, the mouth of the 17th Street Canal had been sealed with the sheet piling preventing lake water from getting to the levee breach. Since no additional water can get through the breach it was no longer necessary to seal the breach itself. The next step was to get existing pumps working, and to bring in additional pumps to drain the surrounding city and the canal. Later, the canal was drained so that permanent repairs could be made to the levee. To allow drainage, backhoes mounted on marsh buggies and draglines mounted on barges cut breaches in some other levees. Marsh buggies are tracked vehicles whose wide tracks enable them to operate in soft, marshy terrain. Helicopters were dropping large sandbags made of strong, synthetic materials in the breach. Heavy equipment on the ground has been placing rock. Ground access was created by building a rock road from Hammond Highway, which is about 700 feet (200 m) lake-ward of the breach. The 17th Street Canal is a drainage canal whose dimensions and an important bridge, integral to the flood control system, would not permit entry of barges and towboats to haul rocks and placement cranes. A pump station began pumping out about 5,000 cubic feet per second (140 m³/s) at the Industrial Canal. One pump was working in New Orleans East. At this point, the process of removing water was estimated to take 36 and 80 days, according to Brig. Gen. Robert Crear. By September 3, 2005, the first of the five new pumps were