Haven't said much about this.
I was in Sumter, South Carolina when Hurricane Hugo came through. Sumter, rather unexpectedly, got the eye of it. I remember huddling down with a couple of other families at a mutual friends, listening to the most hideous noises coming from outside, while the adults sang, got us to play games, and tried not to look outside. I remember climbing out of the house after it passed (you had to climb, it didn't get hit by trees, but a couple showed up at the doors), and seeing what had been a forest around us now a battered and broken plain. I remember finally getting to go home, only to see that there were two very large trees that squashed our trailer pretty much flat. I remember that we /almost/ stayed in that trailer that night, because we didn't have anywhere else to go, until the friend dropped by and said, "You're staying with us". I remember that there wasn't any power or water for three weeks after the storm, and no school for almost two months. Longer in some places where the school buildings were just completely wrecked. Several people I knew lost their homes. Others had major damage that took all of their savings to repair.
I can remember all of that, and yet know that none of it even comes /close/ to the devastation going on in Louisiana at this moment. Sumter was well inland and above ground. Flooding was negligible, and it was rural so you didn't have the density problems that a real city does.
My sympathy is inadequate, and my hopes are not enough, but the people of Louisiana have them, in full. (Also, Red Cross donation, although I wish I could give more.)