Sorry for your loss. You have 2 threads going at this time, so I would stick with this one as long as the problem is going on. Here is the first thread:
https://www.backyardchickens.com/threads/a-dead-chicken.1414987/
In your first thread you said the hens were 20 weeks old and just starting to lay. They should be becoming tolerant to coccidia in the soil. Look at your feed, smell it and note any off odor or blue green mold. Could they have gotten into rat poison or some other toxin, or could they have eaten something like glass or something sharp? I agree with @Wyorp Rock to get a necropsy by the state vet if you have a body, and keep it cold not frozen, until you can get it to your state vet. Sorry for your loss.
https://www.backyardchickens.com/threads/a-dead-chicken.1414987/
In your first thread you said the hens were 20 weeks old and just starting to lay. They should be becoming tolerant to coccidia in the soil. Look at your feed, smell it and note any off odor or blue green mold. Could they have gotten into rat poison or some other toxin, or could they have eaten something like glass or something sharp? I agree with @Wyorp Rock to get a necropsy by the state vet if you have a body, and keep it cold not frozen, until you can get it to your state vet. Sorry for your loss.