A lot of them made it out, you are right. My relatives took off before the evacuation was even ordered--the weather reports told them all they needed to know!
Your relatives used common sense. Something that seems to be lacking in the hell hole known as NO right now.
On Monday, Larry King managed to dig up someone who stayed in NO, who said the weather forecasters told him all week long that they were "100% positive" the storm wouldn't hit NO. I'm sure your relatives will find some grim humor in that -- weather forecasters may not be the brightest bulbs, but none of them would make such an absurd statement, if only because of the sure to ensue lawsuits.
King had no problem with it, of course -- people aren't responsible for their own safety in liberal land.