So we've talked on here before about whether an unarmed attacker justifies shooting them in self-defense. Some of us said one punch can be enough to kill you and it does happen sometimes. Here's a recent instance of this happening. It looks like the guy got hit once, maybe twice, then hits the pavement and goes into a coma. Apparently it was bad enough to pull him off life support.
Bronx school bus driver beaten into coma dies - U.S. News
Bronx school bus driver beaten into coma dies - U.S. News