Dead chicken mystery...what happened?

[mamachook]

We had four 2 year old Australorp hens (we now have three...) and one new almost-year-old mixed breed, who may be a rooster (this is the source of some debate). This afternoon I went into the coop and one of the Australorps was in the nesting box, not moving. Turns out, she is dead. This is pretty upsetting, especially because I can't figure out what happened and if I should be worried about the others or their eggs... She and the others have been behaving fairly normally, eating and drinking and they aren't lethargic. From looking at her body, it wasn't clear how she had died - there were no clear wounds, like from a predator or anything. It seems weird to me that she died in the nesting box.
What could have happened? Are my other girls in danger?

 

[Lacy Blues]

She could have been egg bound for several days and it escaped your notice. She may have been still trying to lay it and finally lost the war.

Your other girls probably are not in any danger. Do you feed free choice oyster shell?

 

[mamachook]

Hmm, ok. I give them a mix of oyster shell and crushed eggshells, mostly the latter, with their layer feed. (A neighbor recommended that we recycle and crush their eggshells instead of buying oyster shell.) Could that be a factor?

 

[Lacy Blues]

I imagine that the eggshells have everything they need to make shells of their own, and in the right combinations too. Maybe she was extra needy?