Squashed chicken??

Hi, has anyone had or heard of a chicken dying as a result of being sat on by others? Yes, sure to have had in the battery cages but wondered if possible in our free rangers.
Our 4 (now 3) ex battery hens tend to sleep in nest boxes, of which their are 3 favourite boxes, despite perches. Just found one chicken dead and was fine yesterday, recently wormed, but in position that my partner thinks was trapped and squashed by the others. Don't fancy doing a PM. Rigour mortise set in but back end, towards vent squishy. Thoughts appreciated.

Thanks Bravemurphy. Sad to lose one, but they have had a few good months with total free range of the garden. She lived longer than most caged hens.