The girls do have a covered run that's somewhat roomy, on dirt, and has vegetation to munch on. Their coop/run is at the back of our grassy area at the edge of the woodsy area, with a lot of trees and low canopy brush and hiding areas: lots of deep ivy, leaves, azaleas, sasanquas, beauty berries, and other shrubs. That's what gave me the false sense of safety. Unfortunately there is a clear perimeter around the coop that's maybe 2-3 feet wide and that's where the hawk snagged the hen. She had sprinted toward the coop into the narrow cleared area and the hawk dove out of nowhere (probably sitting up in a tree watching for awhile) and took her so quickly.
The hens will have to stay in their secure run and coop until I rig a foraging area for them. Thanks for the condolences. It's nice to have folks who understand about the whole chicken thing!
(And I would never hurt the hawks, despite being frustrated with them at the moment. Like I said, I don't blame them. I blame me.)