I would venture to say it was in no way because you didn't feed them for a few days. I let mine go for weeks (even months) sometimes but we are talking about an established 225 gal tank.
Normally there should be plenty of natural food for them to feed on to last them quite a while.
How many gallons is your tank?
What are you doing for filtration?
What other fish do you have in the tank and are any of them aggressive?
What are you parameters (NO3, Salinity, and Temperature would be the most important to note in the case of a fish death)?
Did the fish have any spots on it or injury of any kind?
Have any other fish in the tank shown any signs or trama?
How big/old was the fish?
From there I think we can get a good idea of what killed her (if it wasn't just plain old bad luck that is).
Micah
Edited by Sculpin - October 26 2011 at 4:40pm