I don't prepare for the worst, simply because the worst is so unthinkable; I'm not prepared to shoot looters.
It depends a lot on how hopeless the place was before the disaster; Haiti becomes even worse, but someplace like Montana with heavy snow becomes even safer and more community oriented. Not a whole lot of violent looting at the Tsunami which basically destroyed major parts of Japan.
Goal: live in places which won't turn into hell after a natural disaster.
To me having a few weeks of extra food and basic supplies can never hurt, it is a lot easier than most people think for global supply chains to fail. If you have ever been in a natural disaster you would be surprised at how fast the shelves at a walmart completely empty.