I cant believe this keeps happening to you! I really think you need to install a game camera to photograph whatever it is, so at least you will know what you are up against. Trust me, I hate coyotes with every fiber of my soul. They have cost me more chickens than I even want to think about. But from the damage you describe, I'm not 100% convinced it was a coyote. There are sooooo many different types of predatory animals in AZ and since your property backs up to a wash and is in the vicinity of Saguaro National Park, you literally have a wildlife corridor in your backyard. I am available if you want any predator proofing construction advice or merely a shoulder for sympathy. You may want to take a few weeks off of even thinking about it, I know it is a lot to deal with all at once.It happened again. Coyote got all 15 of my 4 week old broilers and the hen that was raising them. The coyote ended up moving 30 lb cinder blocks and boulders out of the way, ripping out the wire apron surrounding the meat pen, moved a buried 4x4 log, and chewing off chunks of the plastic (just decorative and sun shade, but still, determined animal), and ended up ripping off a small panel of wire in the corner of the A-frame and getting every single animal in the pen. I'm sick. Despite it's efforts--it kicked those cinder blocks at least 5' away--it didn't end up digging in, but got in where wire was attached between the metal and wood frame. The opening was the size of my hand. I truly believed my animals were completely safe, and their death is completely my fault. I'm just disgusted.
I'm done with meaties for a bit. Honestly, I'm not really sure there was anything further and feasible that I could do to protect their coop. Electric fence doesn't seem feasible in a small space in a suburban yard with kids.
My layers and their coop seem undisturbed. But now I'm not as confident as I was before that the devil coyote can't chew right through the hardware wire.