All these comments are completely spot on. One huge shortcoming was the governor not ordering contraflow on Interstate 59 and Interstate 10 out of the city. Seeing as how Mississippi, Alabama and Texas were threatened as well, I know the governors of those states would have been more than happy to cooperate with Louisiana in getting contraflow through their states. I-59 should have been northbound only, from New Orleans, at least to the Mississippi state line, and probably to Meridian, Miss. Interstate 10 should have been eastbound only from New Orleans east to Mobile, Alabama and westbound only to the Texas state line. This would have facilitated getting people out of town much more quickly.
Part of what caused the levees to fail is also the unnecessary volume of water behind them. This was a direct result of the city of New Orleans draining nearby salt marshes and building strip malls, etc., on them. Salt marshes hold a tremendous amount of water and kept New Orleans from flooding during historic hurricanes like Audrey and Betsy.
The "laissez les bontemps roulez" attitude of the Big Easy may be part of its allure, but that attitude from city and state government officials nearly destroyed their historic city.
As a point of comparison: in 2004, when Hurricane Ivan barreled into the Alabama Gulf Coast, the governor ordered northbound contraflow on I-65 to Montgomery (about 170 miles), and the mayor of Mobile ordered mandatory evacuations about 60 hours before landfall. Preparedness is everything. Ivan was a strong Cat 3 storm, and we managed to get our people out. We also took in a lot of Katrina refugees. We're 8 hours from New Orleans. The national media can say what they want, but we know what really went down when Katrina hit. We have friends and family who lived through it.