I am so sorry that happened to you. I am a new chicken/duck momma and I am so worried about a fox, coyote, or bobcat to come in and steal one of my babies. Yet, it is the risk I am taking by letting them free range. It is nature and there is not much I can do about it. If I want them to be safe, I have to keep them in the coop run all day. However, that is not as much fun for them. If anything would happen to my flock, I would be devastated. I would come running to this forum, cry and hope for some comfort. However, I also understand, that the predators are out there and they are doing what they have to do to survive.
I also have teenagers. Every time they leave my house and want to drive over Highway 17 (very deadly mountain highway), go to a huge concert, or travel to a faraway country, I worry sick about them. I know in order to keep them completely safe, I would have to look them up. However, that would be no fun and not fair to them.
I understand your frustration and how sad you must feel to lose your hens.
I am sending you good vibes and hope that the rest of your flock will be safe.