Crumble jokes

What's the difference between a crumbled man and 9/11... nothing, they're both crumbled.

Two lepers meet on the street.

First says "How are you doing?"

Second says "Mustn't crumble!"

The Twin Towers are like snowmen; they fall and crumble.

I told a cookie a joke the other day.

It just crumbled.

Why did the crumb cake isolate himself? He had a crumbling social life.