Crumble (verb)

To break or cause to break into small pieces.

Origin:

Late middle english: probably imitative.

Examples:

1. The old building crumbled to the ground after the earthquake.
2. The cookie crumbled when I tried to pick it up.
3. The dry soil crumbled easily in my hand.
4. The cake crumbled as I sliced it.
5. The cliff face crumbled and fell into the sea.