CNN has an article today about the repairing of NOLA's levee breaks, and how it is likely the repairs were not sufficient to protect against another hurricane, or even a very high tide:
Legal action is finally beginning regarding the levees in NOLA...to seek a declaratory judgement that the reason the levees failed was due to poor construction and not to higher water levels caused by Katrina. The LA state Attorney General's office has begun an investigation.