St. Bernards 13 miles of 17 to 17.5-ft-high earthen outer levees along the Mississippi River Gulf Outlet were breached in several places, including one measuring several thousand feet. That sent a torrent into the neighborhood that produced "complete destruction" and swept houses from their foundations, says Col. Duane P. Gapinski, the Corps officer charged with dewatering New Orleans. No residents will be allowed back in the parish for four months and the levee "will take a lot longer than four months to repair," says Gapinski.
It is still too early for investigators to offer a definitive explanation of how flood defenses failed. Corps engineers are puzzling over forensic details and weighing various failure theories.