Context
A project that was going well suddenly implodes.
Se fue todo al traste.
'It all went to the draining board' — a mess, completely ruined. Very common.
Something has gone wrong — plans have collapsed, things have deteriorated, it's all off the rails.
'Se ha vuelto con forma de pera' is absurd. Spanish uses entirely different images for things falling apart.
Context
A project that was going well suddenly implodes.
Se fue todo al traste.
'It all went to the draining board' — a mess, completely ruined. Very common.
Context
Holiday plans that collapse at the last minute.
Todo se torció.
Everything twisted/went wrong — torcerse is the verb for plans going sideways.
Context
A relationship that started well and ended badly.
La cosa se complicó bastante.
Things got complicated — the understated Spanish version of a deteriorating situation.
Context
The event that was supposed to be perfect descends into chaos.
Se montó un lío de mucho cuidado.
A right mess kicked off — lío is the Spanish word for chaos, tangle, trouble.
Context
A business deal that fell through spectacularly.
Se fue a pique.
It went down (like a sinking ship) — pique = to sink. Perfect for total collapse.