chicken sudden death overnight - causes?

[CanadaEh]

One chicken suddenly died overnight. Some time between lights off and sunrise according to coop camera. She was only pecked by others after she was dead in the morning. It only dropped to -5C in the coop overnight, but might be the coldest that we have had this winter. The was found dead on her back (heart attack?) late in the afternoon as it was super chilly (wind chill -25C) and we did not let chickens out. She was ether 1 or 2 years old. Layman necropsy did not show anything abnormal, other than ~1 inch hole into the abdoment in place of the butt - I assume pecked by chickens after her death. No blockages. Empty crop, few grains of corn thrown to them before night time + some food + rocks in the gizzard. Unusually few undeveloped eggs, but some might have been pecked through the chest cavity. Either accidentally or not this happens to be the chicken that had dirty butt and missing feathers around it for months. By dirty I mean not poppy, but dirt dirty as if she constantly had wet feathers under her tail dipped into coop/run dust. Other than that she was very normal. Any ideas?

 

[Eggcessive]

Most of the times I have lost a hen, they were not pecked once they were dead. So the hole in her vent area sounds like she was attacked and cannibalized. How much room do they have, and do they get outside to free range every day?Was she low in the pecking order or acting ill before? Whenever I have lost chickens, it tends to happen during a cold spell or during a molt when they are most stresses. Sorry for your loss.

 

[CanadaEh]

Most of the times I have lost a hen, they were not pecked once they were dead. So the hole in her vent area sounds like she was attacked and cannibalized. How much room do they have, and do they get outside to free range every day?

Not enough in the coop, plenty outside, they go out every morning 9 am and back at dusk. Today they were not allowed out in the morning to super cold weather, but according to security camera recording she was dead before sunrise while everybody else was roosting. They were definitely pecking some of her organs meat through a hole in her chest when I found her around 4pm.

Was she low in the pecking order or acting ill before? Whenever I have lost chickens, it tends to happen during a cold spell or during a molt when they are most stresses. Sorry for your loss.

Not sure where exactly she was in the pecking order, but could not be too low as there are a few much younger hens. Pecking is rear as there seems to be a handful of really bossy hens and than everybody else is almost equal plus there is a rooster. No, nobody acted ill or lethargic even despite cold weather.