I bought two point of lay chickens a week ago and they have been kept confined in their coop for the past week. This morning one was found dead with no visible signs of injury except a couple of feathers missing. They were both fine the last I looked. Any thoughts on what killed it? The coop is on concrete and has small square chicken wire. I'm new to keeping chickens and concerned the second chicken may die too. My guess is that it may have been unwell when I got it? I appreciate all thoughts.