I've been heartbroken. This morning I had 12 about to hatch eggs under hen.... After church I see one that looks to be half crushed and only 5 others. I've looked for signs and have found none. My guess is a snake.
The one with a crushed she'll still breaths but idk. I'm giving the poor thing every chance by bringing it in and placing in my now running incubator with its other surviving egg mates.
So sorry. I have had the same thing happen and it was a snake. Caught him in the act. Hoping your survivors all hatch.