Can goldfish eat snails??

[beckyd]

I don't mean can they physically accomplish it, I mean will it hurt them? My goldfish tank is next to a window and thus gets some algae growth. A friend gave me some medium sized snails with a pile of little babies. By the next day, the little ones were gone. And the fish were fat and happy. Today, one is dead. He was not ill appearing. Did eating the baby snails give him an obstruction and kill him? If so, is there anything I can do to save the other two from the same fate? This was about a 4 inch(body length) 2 yr old ryukin. The others are similar in size and age.