to reach free-fall relax and tend to have less serious injuries than
cats who fall from lesser heights.
Unscreened windows pose a real danger to cats, who fall out of them so often that the veterinary profession has a name for the complaint—High-Rise Syndrome.
It is a misconception that cats won’t be injured if they fall from one- or two-story buildings. They may actually be at greater risk for injury when falling shorter distances than by falling from mid-range or higher altitudes. Shorter distances do not give them enough time to adjust their body posture to fall correctly.
The video on NG is very interesting. Photo from here.