I had a 20 inch ck named Hank. I couldn't afford to buy his new tank due to family emergencies, so I made arrangements to bring him up to the Big Al's by my house to be put in their display tank (thing must have been 5000 gallons). When I went back to check on him the next day, I found him in a sale tank, nose half torn off, tail GONE, and looking half dead.

I started bawling crying immediately. I took him home the next day, and unfortunately he didn't make it.
What they did, was wait till closing time before they remembered they had him acclimating, dumped him in, turned off the lights, and left, without monitoring the other fish in the tank. Bastards.