Meaning 1 · most common
break into pieces

To separate into pieces, usually because something is weak or damaged.
Examples
My old shoes came apart after just a few months.
A: What happened to your bag?
B: It just came apart when I tried to pick it up.
Common mistake
Not: The toy came apart in pieces.
Say: The toy came apart. / The toy fell to pieces.
'Come apart' already means separate into pieces — 'apart in pieces' is redundant.
More on “break into pieces”Another example · Tell it apart · Goes with · Tip
Another example
In my opinion, cheap furniture often comes apart quickly, so it's better to invest in better quality.
Tell it apart
The chair came apart when he sat down.
He came apart when he heard the news.
Goes with
- come apart