There are many kinds of breakdowns-mechanical failures, emotional upsets, decomposition, and communication to name a few. Cars can break down rapidly, like when you put your foot on the brake pedal and it goes to the floor..oops, or when the engine sputters and dies and the starter will only grind endlessly.
Emotional upsets can have rapid onset triggered by the glimpse of a list lover, a snatch of song, the whisper of perfume or just a random thought. Then all of a sudden, tears flow and breakdown ensues.
In hot weather organic substances rapidly breakdown into rich compost or unspeakably vile piles of unknown origin.
And communication can turn on a word, a look or an inference altering a pleasant interchange into a full on argument.