so sad

I feel absolutly horrible. I went to get Ara, our hampster out of her cage and found our she has wet tail. wet tail is usually deadly. they say is is stress related and if that is the case then I think it happend when my dad and i changed her cage and she met Ruby for the first time when she was in her ball. usually i put ruby in the kitchen when she is in the ball. there is nothing I can do at this point. I know i did not catch it in time to take her in and try to get her better. she already has mucus on one eye. she most likley will be dead by morning. I just don't know what to do. when she does die i'm probably going to get rid of her cage and if we get another hampster then i'll get another cage. I don't need another one die because of contamination. i just don't know what to do or how to tell the girls.