I sympathize. A possum or coon got all but one of my chickens a couple of months ago. I live in town with a 6 ft privacy fence and a pig wire fence around the chicken area. The coop and small run have hardwire cloth with capstones around the perimeter. After one attack by an owl early one morning- right at daylight, I started locking the run door each evening and opening it around 8am. I did not think about the nesting box lid having broken hinges. The varmint moved the lid askew enough to climb in and kill my flock. They could not get out because the door was latched. My fault and it was a painful lesson. Hinges and latches secure now. New flock about ready to go outside- I am nervous. Will put landscape bricks on top of the nesting boxes just in case as well as a padlock latch on the door.