crumple up

Then he seemed to crumple up entirely, and, falling forward, rolled with a loud splash into the river.

I can't help imagining that perhaps just as we get to the middle, they'll crumple up like a jack-knife and nip us.

Jerry, in a glance, saw his big comrade crumple up in a heap, the whole front of his body torn away by a piece of shell.

And now I'd be afraid to land on you with a sofa cushion; you'd crumple up like a last year's leaf.

To the relief of Max the leaping cat seemed to crumple up in the air.