Tom crumbled up biscuits and mixed them into the quark.

The old brickwork was beginning to crumble.

This is not wishful thinking or a dream that may be set to crumble before our eyes.

Where did you crumble them?

I guess that's just the way the cookie crumbles.

The old brickwork began to crumble.

Ziri crumbled to the floor.

Without warning, the lighthouse began to crumble under their feet.

Sami's world crumbled.

Damn!  It hurts to see my identity crumble.