What’s the closest Spanish idiom to the phrase “fall apart” in English? Looking for something that could connotate the loss of confidence in a deal, a ruse, a deception, something like that. “Without the DNA evidence, the prosecution’s case fell apart.” Or perhaps even the collapse of a physical structure. Thanks in advance!
Literally, “to fall apart” would be deshacerse.
There’s also desenredar, which means to unravel or disentangle.
caerse a trozos, venirse abajo. Both are quite-literal translations, too; in Spain at least the first is seen as more casual; both can be used to mean both a physical breakdown (a box, a house) or a psychological one. You’d hear a shrink say “venirse abajo” on TV, but never “caerse a trozos” or, down from casual to I-was-born-inna-mounnains, caerse a cachos
The thing about desenredar is that it’s about something that was entangled (enredado) like, say, string the cat’s been playing with. It wouldn’t apply to an intended knot, a construction or a person.
a vote for “venirse abajo”. You could easily say “el caso se vino abajo” (the case fell apart), just as easily as “la casa se vino abajo” (the house collapsed). It is also fairly universal. It would make sense in most countries.
Maybe not quite what you’re looking for, but between Cubans we would say “se jodió la cosa.” Or the whole thing got f-ed up.
I third the motion. At least in Mexican mainstream media, “se vino abajo” is commonly used. If you do a google search, you will find that’s the case.
In Mexico we use the phrase, but in a more mainstream manner, “se vino abajo.” “Jodio” is considered a bit vulgar for public usage.
don’t be shy, we know you actually say “se jodio la vaina” 
Not something I would say in front of grandma, though.
How about derrumbarse? I think I’ve heard that used in Mexico, and my wife seems to understand me when I used it to mean “fell apart” in the context of the OP. Se derrumbio el caso cuando no le quedo la guanta.
It’s “derrumbo” not “derrumbio.”
“Guanta”? As in a pack of grass?
“Derrumbarse” is also good.
Ok, more serious answer now, if I was talking about a legal case I would use ‘el caso se desmoronó’ or ‘it fell apart’, if the deal fell apart more or less on its own. If the case fell apart through the direct action of others I would probably say that ‘derrumbaron el caso’ or ‘they demolished the case’.
Oops, FireFox doesn’t have a Spanish spell/grammar/whatever checker. 
Funny thing is, I actually how to write each and every one of those correctly…
Thanks to all. I was able to get the point across without the whole thing collapsing