I take it you mean from one punch? As it is obvious people can be punched to death if they are repeatedly punched, but assuming you mean from one punch... There are waaaaay to many variables to say 'Yes you can' or 'No you can't' I mean, it may seem unlikely to getting punched in the face will outright kill you, but what if you were punched into something, such as a wall. But, then, does this count? Was it the punch that killed you, or the force of you hitting the wall. So yeah, too much variability to say for sure. But, IMO yes, yes you can.