Fig.: to fail, to not work as intended referred to a plan, a project, or to go out of business, to go bankrupt referred to a firm

I put my life and blood into this company and I'm not going to let it go belly up because of a stupid mistake by the accountant

Ci ho messo l'anima in questa ditta e non la lascerò andare a gambe all'aria per uno stupido errore del commercialista

Our project was very good, interesting and much appreciated, but it went down the drain when we ran out of money

Il nostro progetto era molto buono, interessante e apprezzato, ma è andato a gambe all'aria quando abbiamo finito i soldi

This slang expression (early 1900s) alludes to the posture of a dead fish in the water