I have a friend who came home very drunk and stumbled into his brick wall, just outside his front door. He must have really been moving as he must have tripped, glanced off the wall with the right side of his head, shoulder, right arm and hip where damaged by the rough brick surfaces.
His right arm and hand looked like hamburger meat from elbow to little finger. The only area that was not hurt was where his stainless steel Apple Watch with sapphire screen was buckled to his arm. The stainless had deep scratches along the side that contacted the wall and the sapphire screen had a tiny mark on the rolled edge of the screen where the stainless was nuked. The sapphire is very tough yet can be damaged under the worst conditions. He was not wearing an Ultra, it was a series 7.