fall through

US /fɔːl θruː/
UK /fɔːl θruː/
"fall through" picture
1.

fail to materialize; be unsuccessful

:
Our plans to go on vacation fell through at the last minute.
The deal might fall through if we don't act quickly.
2.

to drop or break through a surface

:
The old bridge might fall through if too many cars cross it.
Be careful not to fall through the thin ice.