We're so utterly confused. Saw my four hens at 9 am to fill their water bowl and feeder. All seemed well. Our white/black brahma, Silver, jumped back in the coop to lay an egg. I went back inside my house, came back out to check on the chickens at about 12:30 or 1pm and Silver was dead. On her back, feet up, wings spread out. Not an ounce of blood, no trauma. Our chicken run is very secure, so I knew it wasn't a predator, but I checked her all over. Her wattle had gone very pale, her eyes white and glassy. What on earth could have happened?! Should I be worried about my three remaining chickens? I'm so sad for poor Silver, but I didn't notice anything sickly about her at all.