Disasters come in all sizes. Sometimes we have time to plan; often, we do not.
In case of a natural disaster, folks should plan to take care of themselves for three days before expecting outside help to arrive. If damage is widespread, think Katrina or the Nashville flood a few years ago, resources may focus on the more populated areas and miss you entirely. That sounds unfair and incompetent, but even good folks with the best of intentions miss the perfect mark now and then.