I can understand why some people didn't evacuate. Maybe they didn't have cars. Many people depend on public transportation.
Maybe they didn't have money for gas, many people live paycheck to paycheck.
I heard one woman at the Super Dome say her car broke down as she was leaving town.
Maybe they were old, with no family, or infirmed, etc.
What they should have done, though, and didn't was to get to the Super Dome as instructed. Seems to me that would have saved a lot of search/rescue time, if more people had come to the Super Dome in the first place.
One poor man was a double amputee and was found hanging in a tree.
I see a lot of able bodied looters that could have walked to the Dome as a last resort. I don't buy that, "I didn't have any way to get there".
There should have been provisions for getting the poor and infirmed out by the city. Everyone else should have had the sense to leave on their own.