If you live in a major city and think it would be different than New Orleans, you're wrong.
If you live in a minor city like I do, things would be little different if law and order break down and social chaos ensues.
I've been agonizing about a personal evacuation plan for about 30 years now. I am telling my family to leave me behind because of my age and try to get to a rural area well away from a major city where marauders will fan out. I had always hoped some rural property my family owns would provide a safe haven, but it might not be safe from roving refugees if Chicago gets hit with something. I will try to allocate the resources for them to do so. Take as much food and water, medicines, anything necessary for survival with you.
You need to get your life in order, prepare spiritually, not get mired in drugs and alcohol, practice patience and get any tendency to fly off the handle under control, so you can be cool-headed enough to own firearms and protect yourself and your family with them.
There are some things you simply cannot plan for depending on the crisis.
Get basic survival necessities packed and ready to go and pray with everything you've got. Don't depend on your neighbors unless you live in an exceptional neighborhood. It will be every man/family for himself.
They will have to shoot me before I would willingly go to an evacuation center after what I have seen. I would rather die.
Nothing about any of this has surprised me in the least. If it weren't for the flood, which is hampering rescue efforts, it is also protecting some people from being tortured, robbed, killed and raped because the human animals can't get to some of them.
DO NOT DEPEND ON ANY GOVERNMENT AGENCY FOR ANYTHING. Even if you are on a minimal budget people on foodstamps could slowly store extra canned food and water for their own survival if they wanted to.
I know how to can. Home canned goods are really heavy and difficult to transport. During the WWII my mother who was luckier than some got half of a cow from a farmer and stayed up 24 hours canning beef. That was then; this is now. We never had to deal with civil disorder in those times, even during the depression. My mother used to irritate me with her stories about the depression. Now I'm glad she told me some of those things.
Don't loot and steal unless you absolutely have to, and then only with the intention of trying to make restitution somehow, if only by lending a helping hand to someone else. You can't even share much with the hordes who are unprepared or your family and loved ones will starve.
"Smart Growth" (dense population concentrated "downtown" with a public transporation system (especially rail) does not work in an emergency.
Here in Houston, the Smart Growthers (also known as "Inner Loop" types) openly resent those who live at the "edge" of town and want to stand in the way to any expansion of our freeways for higher loads.
Those freeways are an interstate system. As it stands now, they are used daily by the trucking industry, travellers, commuters, and now evacuees who are being moved into San Antonio.
You can't evacuate a city when you don't have public transportation plans to use city buses to take people out of town (and just what is the plan, where do they go?). Even private cars will get stuck in gridlock (far worse than what you would experience on the day after Thanksgiving or any 3 day weekend).
And civic money, which used to go to shoring up public schools so that they could be used for storm shelters (including the much maligned fallout shelters) now goes to lining pockets of connected contractors building billions in stadiums and theaters.
When a city puts tourism over infrastructure, beware.
Houston WILL flood again. Our mayors (one after the other, all connected to the same interests) have served us poorly.