If a novel is one person's moral journey towards acceptance of their place in the universe, then the plot is contrived to give them a gift or gifts to help them on their way to which he or she is particularly ill-suited.
Nail those - the human flaw and the perfectly unsuitable circumstances - and you've got the essential irony that powers a novel.
A disaster story brings these into sharp dramatic relief. As one of my writers pointed out this week, the hero of the Jaws movie is afraid of water.
But there's more - it's not the flaw that's so important in the grand scheme of a disaster story, so much as the hero or heroine's gift.
The narrative path as outlined in The Five F's of story at The Novelry, finds its immaculately opposite form in a disaster story. The negative image. Perhaps that's not surprising, for is a novel is propelled by what the main character wants, in a disaster story it's all about what they don't want to happen.