what came first, the dead snail or the crabs lunch?

I noticed today that I had two empty turbo snail shells, when I picked one up to check it out there was a small crab inside that looked like he was eating. there was no trace of the snail.

so what do you guys think, did the snail die first or did my crab kill it?

I still have several turbo snails left but I would like to get more. Im not going to waste my time and money if the crabs are just eating them though.

 

I think that most likely the snail died first and the crab was cleaning up. But it could have been the other way around with a much larger crab if you have one.

 

I do have large crabs but this was a tiny crab in a huge turbo snail shell. They were Petco snails so it's a good chance they just died on me.