Go south

I should have walked away from the casino when my luck went south, but I stayed and ended up in the hole.

I still had 5 miles (8 km) or so to go to cross the river when all of the controls went south. The bird pitched up, shuddered, rolled right like it was going to spin […]

There was only one more guard between her and her goal, and despite her preparation, it almost all went south. The woman walked out of a door Fina hadn't even known was there, nearly bowling her over, and it was all she could do to bring the butt of the rifle up to smash the insurgent's nose in. She cried out, and Fina brought the butt 'round again, and this time the bone must have pierced the brain because the body went limp with a final, plaintive gurgle.

He won! A disbeliever, from childhood, in the frequency of miracles, he gathered up seven hundred and forty dollars and "went south" with it.

[…]she decided to tape the DVD off to VHS and give that to the kids -- that way she could make a fresh VHS copy when the first one went south.