False dichotomy. The Levees were not the reason Nagin and Blanca were at fault…
Nagin was at fault for not evacuating the exceptionally vulnerable 9th ward, the retirement homes hospitals and all the other extremely vulnerable elements of NO. Instead Nagin’s plan was to leave the buses in their parking lots. Nagin was also at fault for telling people to come to the super dome instead of evacuating. These and other mistakes directly led to so many vulnerable people drowning instead of being safely evacuated.
As for Blanco her fault was to stick her head in the sand before Katrina hit instead of requesting the assistance of National Guard elements from other states but waiting until after Katrina had hit.
I’ve already detailed this elsewhere.
In any case, levee failure was not the cause for the flooding of central NO, it was the failure of the walls of the canals that led all the way north on lake Ponchartrain to downtown NO. NO being below sea level, they installed pumps downtown to evacuate rainwater during storms. The pumped water used the canals to drain into Ponchartrain but were recognised by everyone with a brain to be weak points in NO’s defences against flooding. The CoE proposed gates at the Ponchartrain shore but were blocked by idiotic homeowners.
Note that I didn’t blame Nagin/Blanco for the canal failures but the homeowners near Lake Ponchartrain who sued to prevent the installation of gates on the ends of the canals that would have prevented lake Ponchartrain’s waters from drowning NO if the canal walls failed.
Lastly, the CoE DID predict that the levees of the lower 9th ward and that the canal walls were vulnerable and the federal government had proposed funding many times to fix these most urgent problems. The problem is that after seeing corrupt local governments embezzle >50% of the funds allotted to enrich themselves on all recent major works, the USG would only fund 50% of all future projects and corrupt locals were still hoping for a new gravy train and refused.
Had Nagin evacuated those who he knew were most at risk and Blanco better prepared, flooding or no, there would have been little loss of life.