To fall through is to fail to happen after being planned. The sale fell through, the whole thing will fall through.
It is used most of house sales and of arrangements involving other people. Nobody causes it in the phrase, which is part of why it is so often reached for.
1phrasefall throughTo fail to happen after being planned.
“If the survey is bad the sale will fall through.”
fall through is a phrase.
Practised in Phrasal Verbs