I'm sorry for your loss, I know how you feel. I went through great lengths to predator-proof my coop (hardware cloth bolted over all windows and openings and around the run, also buried 12" down, 12" out around coop, motion sensor lights, secondary fencing around the chicken yard) and I still lost one IN BROAD DAYLIGHT!!! I free range my girls and because I felt that the coop was as secure as Fort Knox, I let my guard down. A hawk picked off my Buff Brahma at 11:00 in the morning on a bright, sunny day. I heard the commotion but it was too late. She was a hen that typically would find herself alone because she wasn't paying attention to where her sisters were. Sadly, I knew it was only a matter of time for her; I hate it when I'm right. But that's the price that is paid when the hens are free ranging. We have a ton of coyotes and bobcats in the area but I haven't seen them come around at night. We have three Siberian Huskies so I'm hoping that their scent is deterring those predators. I would keep your chickens locked up at night from now on, especially since you saw the coyote sharking your coop the very next night. Hopefully that will be enough to discourage the coyotes since they can't open the door.