Looking for a well-known refrain or proverb indicating that some big trouble has just started

I am translating into English a famous refrain from Spanish, Ahí fue Troya. That means something like Then a big trouble started.

I am looking for some correspondingly recognizable refrain I can use in English for the translation. Because this is a work of literature, having a polished style and wording is very important.

Depending on what kind of trouble it is, you could say:

Then all hell broke loose

That implies that the trouble that started was chaotic or disruptive.

If things just started going badly, you would say:

Then everything went to hell

or

Then it all fell apart

then the shit hit the fan.

Oxford English Dictionary:

a. orig. U.S. Military. (when) the shit hits the fan: (when) a situation suddenly becomes critical; (when) trouble suddenly or rapidly breaks out.

Not as elegant as a classical reference but even people who have never heard it will understand what sort of situation would ensue.