fall apart

1 - If something falls apart, it breaks into pieces because it is old or badly made. 2 - If an organization or system falls apart, it becomes disorganized or unable to work effectively, or breaks up into its different parts. 3 - If you say that someone is falling apart, you mean that they are becoming emotionally disturbed and are unable to think calmly or to deal with the difficult or unpleasant situation that they are in.