I haven't seen very many birds that ran into a window and died. Most of the dead birds that I've seen were killed by getting hit by a car or truck. Where I live, wild turkeys are a hazard in the late spring. I've seen a few dead crows, killed when they took off into the path of a car, and even a large owl one morning. It was dead when I came upon it, as were the others. I carried the owl off the road and into the ditch so it wouldn't get run over any more. I used to collect the wing and tail feathers from the dead turkeys for making arrows. I always carried the turkey off the road and across the ditch, so the scavengers wouldn't get hit while cleaning up the mess, and I always gave an offering to the bird Gods for the gift of the feathers.
I hadn't really seen many myself until I started working in landscape maintenance. I spent four years before the private estate working as an assistant ornamentalist at a premier private golf course in a gated community. We actually handled a lot of the maintenance around the houses in one particular section of the community as well as around the clubhouse. These were big houses, like multi million dollar homes, and many of them had massive windows. On smaller houses with smaller windows, screens are usually being used and/or the windows actually have muntin bars, both of which help to prevent the birds from running into those windows. On those larger windows, they're generally just a single, massive sheet of glass with no screen and no muntin bars, so it's hard for the birds to actually be able to tell that there's something there. I've seen dozens upon dozens of smaller birds like sparrows and thrushes that have been killed via building collision over the last 6-7 years. Almost exclusively around those massive houses with the large windows. Although I've seen a few that were taken out by sliding glass doors on smaller houses as well. This was the first time I've seen a larger bird fall victim to this.
Omg, the dead owl probably would have made me cry too. There's just something so majestic and regal about the birds of prey that almost kind of demands a certain level of respect. Kudos for moving the poor thing. Just seems so disrespectful when we essentially desecrate their corpses after killing them.