I had 4 4mo old chickens 2 d'unccles and 2 cream legbars. The other day one d'unccles just died after we cleaned the coop she was fine the 2 hours later...dead. The other d'unccles and one cream leg bar are now dead. I just found them in the coop, they were fine this morning. We have 3 other chickens in there and the last cream legbar. There are no signs of sickness. No runny nose, sneezing, runny eyes, combs look normal. I called our local agway. They thought it might be too windy/cold for them I might have a draft? Any thoughts I'm devistated.