Fall apart

[Becky]

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.

[Ernesto]

to break into pieces: