I was at PetSmart, and I knew better, but I wanted to check their snails out. ALL of their snails in both tanks were dying, and the guy actually was concerned about them and interested in them. In any case, the largest wild colored snail seemed to be alive, and so I took him home on the off chance I could save him.
He made it about a week, towards the end of the week, he was coming out of his shell, but he never ate in that time, as far as I could see. I even put him right next to the food so he wouldn't have to travel.
I happened to look over at him and see he was partially out his shell, and it didn't look good. So when I tapped his shell and he didn't move I knew he was gone. I even poked him and nothing.
So, yeah, he's gone, poor thing. Whatever killed the other snails in his tank killed him, it just took longer.
This is one of the reasons I avoid petstore critters. I always try to save one here and there and they never make it.