Dead hens

[Knightlight]

Aspergillosis maybe. Not contagious in the viral sense, it's in the environment. Wet conditions would be prime. It's fungal/mold.
More info:
https://vcahospitals.com/know-your-pet/aspergillosis-in-birds
https://www.merckvetmanual.com/poultry/aspergillosis/aspergillosis-in-poultry

This is my best guess as well unfortunately. The coop is dry now, but it was a lake for about a week when the rain and melt off was bad. We managed to raise the ground level pretty quick and bail out the coop, and i kept them all outside as much as possible, but i think the damage was done.