Ring a-ring o roses, / A pocketful of posies. / A-tishoo! A-tishoo! / We all fall down.'' — traditional nursery rhyme (British version)
The beams supporting the roof had rotted, causing the entire house to fall down.
(RQ:Orwell Animal Farm)
Out of spite, the human beings pretended not to believe that it was Snowball who had destroyed the windmill: they said that it had fallen down because the walls were too thin.