Well, that's good. Pigs have been known to eat chickens. I'm glad this one wasn't one of those. So sorry you will have to rebuild. What a P.I.T.A. At least your flock is ok!
My first thought was bear, but that's interesting. Wild boar are dangerous, destructive, and very invasive. You can legally kill it, or Fish and Game will dispatch it for you.
At least they will here...
I'm glad it left your flock alone! And I'm glad you figured it out.