Thanks everyone. And I'm so sorry to the others who have faced a similar problem.
As for the girls. They are not free-ranging right now except for supervised 10 minute jaunts since they're still pretty young. They were completely locked in their run when this happened (sometime between 7 p.m...
So sad
Our run was what I thought was completely predator proof. Hardware cloth and chicken wire doubled on the bottom 2 feet of the run, just hardware cloth for 1 foot above the double layer, then the rest of the sides and top is chicken wire. The bottom is completely covered in hardware...