In a perfect world, that would have been good enough. But you aren't taking into account the disabled, ill and elderly. You aren't taking into account those that had no way to leave. Or the emergency personnel that stayed. You aren't factoring in an area that had no emergency plans and ineffectual officials.
It IS everyone's own responsibility to take care of one's self along with those in the same pickle. Nearly everyone could have moved inland ~one mile IF they had so desired, by car, walking, wheelcahir, or on some's back. Most refused for some delusioned reason or another.
The difference would be from hundreds lost to many thousands who "stuck it out" as Nature buggered them.
Most post-modern people have lost their FEAR of Mother Nature as they blame America for their weather. Many of them will have died this week.
My observations are with profound sadness as I believe that thousands are dead and dying. Lack of water shall kill fast.
Amen. Even as a bedrock conservative, I feel more than a tinge of shame that apparently most of those poor, distraught, injured survivors, trudging through waist-high sludge to find shelter like ants expelled from a flooded ant hill, are black.