down the tubes/flush/chute

Definition

Slang

  • adverb ruined, abandoned, beyond hope. These are racier versions of ‘down the drain’, ‘down the pan’ or ‘down the toilet’, heard in the USA since the late 1970s and in Britain since the early 1980s.
http://www.dictionarycentral.com/definition/down-the-tubes-flush-chute.html