Whenever you have lots of prey in a small area, you are going to have predators. Anyone who has fed birds has had the occasional predation loss, whether to cats or birds of prey. I look at the predation losses to birds of prey as just part of the birdwatching experience.
I was sitting in the living room reading and heard a loud "wham!" on one of the windows in the kitchen area. I thought to myself, "Well, there goes one of my birds hitting the window." But the noise was exceptionally loud, and I go to lengths to make sure my windows are not shiny clean to reduce reflection and window strikes.
I went to investigate and found a good sized puddle of blood on my back covered porch with a few feathers and a Cooper's hawk struggling to fly away with a large burden in its talons. Although I didn't get a clear look at what the Cooper's hawk was carrying, my guess is one of the obese white-winged doves that hang out in my yard. The hawk should be able to eat off of one of those birds for a week, at least. I'm assuming that the dove hit the window at speed in an attempt to evade the Cooper's Hawk, was stunned, which gave the Cooper's hawk the opportunity to ensure the bird was dead and under control for carrying away to a convenient place to perch and eat.