Sorry to hear. I hope it doesnt turn you off of chickens, I also lost my first 5 but to a skunk. Try to think of it as a learning experience, if you can.
Hawks have been crazy around my place this year, I had one in my backyard the other day that kept coming back several times during the day to try and get my birds.
I have a little pomeranian dog that insists on staying out all night and all day, except for the 10 minutes it takes him to eat when i get out of work at 5. My dog barks all night and it can get annoying however i have not lost a single bird to a preditor (knock on wood). I have 11 free range ducks that stay outside and 20 chickens that free range from noon to dusk. who knew such a small dog could be so beneficial to my flocks
I had a hawk problem too.. I tried everything from stringing the place up with old cds, to mylar balloons, to streamers of bright red flashy stuff, to bb guns (not to kill.. just to deter....) to loud noises, to conducting a stake-out.. etc etc.... Finally I found a net big enough to drape over my coop, run, and yard. Its black so it isnt too easy to see. (if you care about asthestics) I also keep the mylar balloons out there.. they have long since deflated but the flashy material and the noise they make when blowing in the wind seems to help with other critters as well..
I found my net on Ebay.. its 50x50ft but they come in much larger or smaller sizes and you can even get them custom cut to your specifications. This is where I got mine seems the price went up a bit though...
So far its been great! strong nylon multi-filament net that is UV resistant... no dryrotting, no snapping, no problems! It has literally been a life saver!
I shoot bottle rockets at them when I see them. Probably not super effective because it doesn't even get close to them, but the whistle and bang at the end sends them on to their next hunting spot.
Oh my I am so sorry for your loss. I think the other day one was roaming around in the skies. Our black one ducked in cover and alerted us it was around. They get scared a lot but its good they tell us when things they dont like or scare them are around when they free range. I didnt think hawks for that matter could be such a threat.