Saturday before dusk I went to lock the remaining 5 RIR's in the coop, there were only 4. My girls had the whole 1/4 acre horse corral since last spring to roam in. I walked over to the far back corner and found her ripped up. In the morning I went to the coop and out of the corner of my eye I saw something. At first I thought it was Walking Dead Chicken and as I got closer I saw it was a hawk, a pretty proud hawk come back for the rest of my chicken. So the remaining 4 are on lockdown in the run indefinitely.
While your chickens are locked up, keep your eyes open. There are resident hawks and then some that are just passing through and may have stumbled on your chickens and decided to hang around for a bit.