Horrible, horrible story.
My hunting buddy is a cop and my neighbor is a nurse on a medevac helicopter. After hearing all the similar horror stories from events they were involved with that never made the TV news, I'll never hunt from a treestand again, nor will my kids.
Basically, hunting is a very, very safe activity, even with rifles, until you start climbing trees. The amount of people that fall getting in or out or setting up or taking down, whom have broken bones, punctured lungs, blown knees, paralyzed from waist down, etc, is pretty shocking, once you start asking people if they know anybody that has had a treestand accident.
I can't imagine the pain this family is going thru.
Be uber careful and please keep in mind that you don't have to use a treestand to be a successful deer hunter. But if you do, use a harness that has full contact from the ground to the stand.
Prayers for all involved.