Randal O’Toole has a provocative claim that New Orleans residents had trouble evacuating because fewer of them own cars than in typical cities (urban planners accomplished their goals).
This is clearly not the main reason for the unusual death toll from Katrina (the death toll in Mississippi seems to be an order of magnitude higher than I would have expected based on results of recent storms with similar winds and the long-term trend of declining storm deaths), but it deserves more discussion.