At least in my area of PA, the concern is less from direct impact deaths and more that theyre going to take detours to go around the windmills and we don't really understand where that will take them. For those who don't know, PA has both a lot of hills and a lot of woods, so theoretically we could establish quite a lot of windmills if we wanted to. But we aren't, because that would enter us into the realm of wild speculation about what would happen to the woods and animals, and nobody really wants to take the blame if something really visibly bad does happen as a result. Also, the natural gas companies don't appreciate that kind of intrusion, so there isn't a lot of incentive to establish them here, even though theres potential.