Leela
im sorry for your loss, There may not have been any fighting at all that would have alerted you. She was probably already passed when the others ate her eye, the eyes are the usually the first thing the colony starts to remove to prevent predators from spotting the deceased glider, then they move on to the internal organs if they have time, again to prevent the predators from smelling the deceased glider. I't can be gruesome when that happens but, it is "normal" and how they protect the surviving colony members from scavengers.