Why were WE supporting a community below sea level

Katrina negligence ruling could cost feds
 
NEW ORLEANS - The federal government could be vulnerable to billions of dollars in claims

 after a judge ruled that the Army Corps of Engineers' failure to properly maintain a 

navigation channel led to massive flooding in Hurricane Katrina. 
 
The entire article is available here:
 
http://www.msnbc.msn.com/id/34028940/ns/us_news-crime_and_courts

Food for thought and your comments;
 
Since the Army Corps of Engineers is funded by the federal government this will be yet

 again a drain on our tax dollars.  I have no wish to debate the rights of these people to

 compensation for the governments apparent screw-up, but why exactly do WE maintain an

 entire city and residential area that is below sea level.  The government has paid billions

 of dollars to people in flood prone areas to move and purchased that property to prevent 

rebuilding, so why do we spend billions of dollars to do the exact opposite here?