hit the fan
Definition from Wiktionary, the free dictionary
This expression is almost certainly from colloquial expressions involving shit hitting the fan.
- (idiomatic, intransitive) To have a dramatic, usually negative, effect.
- They were just clowning around, when suddenly it all hit the fan.
- Then the shit really hit the fan.
2004 December 2, Neal Cavuto, “Interview With Jeff Flake”:
- Let me ask you, Congressman, the case of a lot of these corporate scandals, I followed enough of them to know how -- how it works out. Once everything starts hitting the fan, the CEO, the chairman or maybe a large share of the board of directors simply leaves, resigns
- Use with other subjects than shit is probably intended to evoke the image without actually saying the taboo (in some contexts) word.