If it happened at night the most likely culprit is an owl. During the day I would say most likely a hawk. I have seen eagles here once in a very great while.
First :welcome :frow to all of the new members.
Sorry for you losses. I have some heavy duty netting covering all of my pens. Several years ago something was killing some of my birds. We couldn't figure out what it was because we didn't find anywhere something could get in, so I put a couple...