we got 4 chickens from a guy getting out of the chicken business because we wanted the coop and the chickens just came with it. We have had them 3 weeks and they all seem to be doing good but when we got home today the brown leg horn was dead. Husband looked her over good and could not see any bites or feathers pulled out. They are in a 12 x 12 dog lot and the coop they came with is in the middle of it. They have not been outside of the coop because we have other chickens and I wanted to be sure they were ok to come out. What killed my girl?