My mom and I went out just a short while ago to check on our chickens and we found our buff Orpington rooster dead under the hen house. He was on his stomach and his face was black. I didn't get to take a pic because my grandpa buried him pretty quickly. What could cause this? He was the picture of health yesterday afternoon and all the hens seem fine so far. He was only a year and a half old and a really good rooster.