The subtle signs have been there all day that this is really something unusually horrible. The surge covered such a large area, and went further inland than most seemed to expect. Most of the coast from Slidell to Biloxi is shattered buildings. Even in an extremely successfull evacuation, there would be a lot of people who didn't leave.
the nhc downgraded well after winds had dropped below cat 5, they were extremely liberal with wind speeds at landfall as recon only showed 130-140mph. hurricanes arent rated based on size, they are rated on winds....not that downgrading to a cat 4 had any affect on anything....nor does a cat 4 carry any less warning and near begging for people to evacuate blame canada, blame osama, hell...maybe even blame the people who ignored 2 days of evacuation pleas....but dont blame the NHC.