That is so sad.
I have a covered run but my flock is allowed to free range all day. Roosters help warn the flock of any predators near by. Also providing places for your flock to hide are great things to include for extra protection from areal attacks.
There is an eagles nest within a country block of my house, the pair always have three eaglets every year. My flock free ranges all day even when I am not home. I haven’t had an eagle attack yet but I have only had chickens for eight years. There is a farmer down the road that free ranges...