They have to be informed before they can make the decisions.
Many of these people are so backward that they do not have the technology to watch the storm progress. Not until the mayor declared mandatory evacuations did they know that there was an imminent threat.
They didnt know until 10:45 this morning. Most, if they've been able to leave @ all (many don't have cars), have not been able to get more than 100 miles away from New Orleans. Therefore because of the mayors indecision they are still in harms way.
You must be a Damn Yankee!
Word gets around in the backwoods fairly quickly. If someone is so deep they can't be reached in 2-3 days by relatives or acquaintances they would be on their own anyway, and maybe the storm won't find them either. We don't need the Pres or the Mayor or Gov or the MSM to tell us what is going on. Those offices are already coordinating relief of the main population areas.