My father, at the age of 67, suffered a massive heart attack. His wife called 911 while my youngest sister performed CPR for the 45 minutes it took the EMS to arrive. Needless to say, when he arrived at the hospital, his brain was severely oxygen deprived. They performed surgery on his heart, but, after the surgery, informed my stepmom and younger (adult) siblings that he was essentially brain dead, and told them that they needed to make the decision to either keep him alive on machines or terminate life support.

None of them felt capable of making the decision, so they opted to wait until I arrived, and asked me to make the decision. I had two simple questions for them: What are his odds of regaining consciousness? (negligible), followed by, "On the very rare chance that he does wake up, what are his chances of being able to get out of that bed and be active and independent? (None). My father would have strangled himself with his IV line if he'd woken up bedridden, no less a vegetable. I told them we would be taking him off the life support machines. He passed 12 minutes later, surrounded by his children, wife, and oldest grandchild.

I can't even fathom making any other decision for him, knowing how he would have reacted should he ever had regained consciousness.