Yeah but once the city was built and thriving, couldn't just abandon it either. New Orleans was once the 2nd biggest port to New York. It was the supply channel to the entire Mississippi River system.
The levess could only handle a Cat 3 storm??!!! WTF is that all about. The odds of a Katrina one hitting shore were ..I don't know ...about 100%. Clearly the assholes were just skimping out and playing the odds that it wouldn't happen under their watch.
$5 billion could have put New Orleans on par with Amsterdam - city saved and secure in case of something like Katrina.
So to sum up - we could have invested $5 billion on something we had 100% knowledge of to save lives, money, an extrememly important American city.
---But we spend $300 billion and actually lose a bunch of lives elsewhere based on incomplete information. LOL - We could have saved New Orleans 60 times over with that money

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TIME TO GET OUR PRIORITIES IN ORDER.