crumble

verbs

fall apart
"the building crumbled after the explosion"; "Negotiations broke down"
break down, collapse, crumble, crumple, tumble
break or fall apart into fragments
"The cookies crumbled"; "The Sphinx is crumbling"
crumble, fall apart
fall into decay or ruin
"The unoccupied house started to decay"
crumble, decay, dilapidate