When things "hit the fan," it often means that something has gone terribly wrong. Thankfully, there are many synonyms for this phrase that can be used to express this sentiment. A few common alternatives include "go south," "fall apart," "explode," and "unravel." Each of these phrasings conveys a sense of chaos and disarray, but the specific nuance of each can vary depending on the context. In any case, if you're ever in a situation where things "hit the fan," it can be helpful to have some additional phrases in your vocabulary to express your feelings and communicate what's happening to others.