I've been raising chickens for 3 years now and know that sometimes a chicken passes with no warning or apparent reason which is what I witnessed this evening with one of my 4 1/2 week old cornish rock meat birds. When I got home from work the temp was around 70 degrees and decided to put the chicks out in the enclosed run so they can get some fresh air and sunshine. I opened their coop about a week ago so they could get out but they never did unless I push them out, they seem more interested in the food in the coop. Anyway I put them out and when the sun started going down I had to put them back in the coop. After that was done I went to the window to check up on them and noticed one was looking tired and laid his head down and started to stagger, it fell over and started flapping its wings like crazy and flipped over on its back, stretched its legs out and then its legs started to slowly relax, clench and then lower and stop. This all happened in less than a minute, I'm thinking it had a heart attack. Makes me wonder about how healthy these birds really are for us to eat. Is there really two breeds of birds that are crossed to produce a chicken that grows this fast naturally or are they mutated in some way to make them appealing to someone who wants to grow food fast, after all their breeding is a very guarded secret within the industry. I think I may just be paranoid, or is it just me? I'm still going to process them though, they look so tasty!