[T]he corps designed the system to protect New Orleans against a relatively low-strength hurricane . . . and did not respond to warnings over the years from the National Oceanographic and Atmospheric Administration that a stronger hurricane should have been the standard.The report also says the Corps was not good at keeping up with either changes in the soil structure in New Orleans or new developments in dealing with floods and storms, according to the Times. You can read as much of the report as you want (or as your bandwidth will allow) here. I recommend starting with the executive summary, which is a 64-page PDF file. The other files are much longer.
What really bothers me about this failure is that it was so obvious that New Orleans was at risk and yet no one in authority took action to address the problem. If our government is not doing an adequate job of protecting our country against certain disasters like hurricanes, why should we believe that it is protecting us against more amorphous risks, such as terrorist attacks?
The Department of Homeland Security, which insists that Washington, D.C., is at low risk of a terrorist attack (see Diane's post on this subject), is the same agency that completely mismanaged the Katrina disaster. At least the Corps of Engineers is looking at its mistakes; I don't see any effort at Homeland Security or its completely dysfunctional subsidiary FEMA to look at why things went so wrong after Katrina.
And I fear we won't know just how incompetent they are at evaluating terrorist threats until someone else attacks us.