Thanks to all the feedback.
To add more info about this twilight zone story .......
This all happened in August. The weather was normal patterns. Feed was the same. Chickens are healthy. Yes......this past week the "ladies" have been in molt, that that has nothing to do with the sudden overnight stoppage of laying.
Having answer those questions......I will try a few more of the suggestions given. That hay could had been moldy.....so when I removed it....perhaps the mold spores contaminated the coop over night. Will bleach it out after a soapy clean out. Will come back to give you (the great advisers) the results.