Close the door. I had one hen pullet being killed and brought away by a mongrel cat. I don't have a run used to let them free range all day but after three weeks this happened so I always leave them closed in their coop and let them free range only when I am around and have them in sight the important thing is that they are still alive.
My brother takes the cake on predator proofing and discipline of whichever poor creature dared touch his chickens, but I think you now might be taking the cake.