Found one of my hens dead

[Weeg]

If you are real worried you could send her to a lab to get a necropsy done? Then you would know for sure what happened and you wouldn't have to worry about your other girls. Or you would but you would at least know how to deal with it. Sorry fro you loss, Avery

 

[Wyorp Rock]

I'm sorry for your loss, sadly there is no way to know why she died unless you send the body to your state lab for more information or you can perform your own informal necropsy to see if there's something obvious.

If you want to send the body for necropsy, then refrigerate it and call your state lab for instructions https://www.metzerfarms.com/PoultryLabs.cfm

If doing your own, you may find this video helpful. Take photos of what you see and post them, hopefully we can help you.