Garden Snail "Shed" Its Shell- Will It Live?

[Steve]

My son brought an ordinary garden snail to school today for show-and-tell (had to start w/ "s"). Well, when I took the tupperware container out of his backpack this afternoon to let it go it was completely out of its shell (EEK!). This thing was DEFINITELY still alive & cruising around...I put it outside along w/ its shell, but I'm afraid its done for. Could it possibly crawl back into the shell & survive? I'm feeling guilty for giving the thing a death sentence. =(