Fish eatting each other

Question
Hello my name is matt. i have hade my fish tank for about a year now and have not had a problum i have three gold fish and 2 smaller fish. untill last night. i was gone for the weekend. when i came back one of my fish had all of its eyes missing it had no fins at all and bit marks in it. what is happening and what should i do

Answer
Matt,

It is hard to answer this question with no information about the other fish. What size tank do you have, and what other kind of fish is in there with the goldfish? Which fish has the bite marks? Is it the same fish that doesn't have eyes, fin loss? Please get back to me as soon as you can so we can figure out whats going on and fix it.