Flood number 4 struck first at the lower Ninth Ward and continued across upper St. Bernard parish when the surge from MRGO and the GIWW funneled into the Industrial Canal.

Breaches in the levees on the east and west sides of the Industrial Canal caused intense damage and enormous flooding. Desire to Bywater took some water on the west while the Lower Ninth, Arabi, Chalmette and the rest of St. Bernard were drowned by water flowing down hill trapped between the wetland levees to the north and east and the river levee to the south and west.

Residents in the Lower Ninth swear they heard an explosion when the levees gave way. They believe the eastern side of the levee was blown to save the French Quarter and the CBD. This shows more foresight and planning than the authorities demonstrated elsewhere and seems highly unlikely. The most paranoid of the conspiracy crowd try to link this to the Danziger Bridge incident claiming the contractors involved in that incident were federally sponsored dynamiters. Rubbish. The noise was just the sound of the levee breaking open, the initial rush of water and the barge that was carried through and dumped just over the levee.

Preventing future flooding in this area could be the most straightforward of the plans required to protect the city. The land of the lower Ninth, despite its name, is not as low lying as other parts of the city. It is just that the Industrial Canal has created problems for the area since its construction. Catastrophic flooding of the lower Ninth in the future can be eliminated by sealing the Industrial Canal with a dam at the lake and placing flood gates in the GIWW at Michoud to be closed at the approach of a storm from the east.

However the destruction of this area was so complete, there is really no rush to protect it right now when there are so many other priorities. The Corps doesn't see it that way and you can see the Corps working there day and night to repair and raise the levee along the eastern side of the Industrial Canal. Furthermore Nagin's "Rebuild Everywhere First" land use non-plan is causing the utility companies and other infrastructure repair resources to be spread thin when concentrating on the undamaged and populated areas of the city could bring positive results.