To be honest, any government. This "oooh half a million people" is just doing my head in. It isn't really that difficult to move lots of people from one place to another, even under quite trying conditions. Wars would be much less common if it was. Quite apart from anything else, it has to be remembered that it was only about 80k people who were left behind in the city itself. If you can evacuate 420k people you can evacuate 500k.
Furthermore, if this had just been a failure of evacuation, then there would have been many fewer fatalities and people would have been saying "hell, what bad luck". The failure that made the headlines round the world was the fact that five days later, there were people hanging around the Superdome and the convention centre without food, water or sanitation. Arranging the logistics, like arranging an evacuation, would be difficult but nowhere near impossible, particularly as this is sort of what the "emergency management" people do for a living.
dd
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