I am very sorry for your loss, it isn't easy, but it's part of raising chickens. I say it was through no fault of your own. You did the best that you knew how, and you have learned some powerful , painful lessons. When you say "poultry wire"' is that what we used to call "chicken wire"? If so, the only thing that stuff is good for is keeping chickens in or out of a place. Most predators can rip through chicken wire like nobody's business. Where I live, raccoons , coyotes are my biggest threats.And my own dog! I like to use welded wire then run 1/4 inch hardware "cloth" on the INSIDE of the welded wire, attached with hog clips.
Don't give up.Get some more chicks, and turn the run into fort knox! Best regards, JA