It is awful, finding your birds killed like that. I lost two young speckled Sussex to a black vulture most recently .The others don't understand why I won't let them out of their run any more. Daytime not safe, night time worse.
Lost 3 so far to a hawk, thinking of buying a shotgun. You know, one or two is bad enough, but I have lost track how many have been killed by predators now. I build, and build, but somehow I can never protect them all. So sorry for your loss, I know how much it hurts.:'(