A couple of years ago my 75 year old grandpa was bowhunting out of a stand that had been hanging for almost a decade. We had all been lax in our inspection of our semi-permanent stands, and the strap had badly deteriorated. When it broke, he fell about 14' and landed with his feet out in front of him, sort of in a sitting position. He broke his pelvis and 2 vertebra, which they ended up having to fuse.
The awful thing is that this was entirely preventable. It was apathy that caused the fall. Had one of us performed a bit of preventative maintenance/inspection, and had he worn a harness, there would have been no accident.
Before all of this happened, he had always been spry. The man was a work horse. Now he can barely walk through the woods. Needless to say we are a LOT more diligent in our safety procedures now. This stuff is not to be taken lightly guys.