My 17 week old black chicken (with red tips on the breast feathers) died suddenly today. I was out there at 3pm and she was fine. no sign of problems. Comb a bright pink like the rest of my little flock. Then at 4;30 I went out only to find her laying dead and the other 6 were standing around her in a half circle. I examined her and found no sign of being pecked or bugs of any sort. She was laying on her side eyes closed. And her comb had gone pale pink. No new foods. I give her starter/grower & veggies. Clean water every day and wormed the whole flock two weeks ago. The only thing different is three days ago I put straw in the pen for bedding instead of the cedar chavings I had been using. Any ideas? I want to protect my remaining babies.