Verbs

(v)crumble, crumple, tumble, break down, collapsefall apart“the building crumbled after the explosion”, “Negotiations broke down”
(v)buckle, crumplefold or collapse“His knees buckled”
(v)pucker, rumple, cockle, crumple, knitto gather something into small wrinkles or folds“She puckered her lips”
(v)rumple, crumple, wrinkle, crease, crinklebecome wrinkled or crumpled or creased“This fabric won't wrinkle”