First you're there, and then you're not there, and they can't change you from being not there to being there, because there's nothing there to be changed from being not there to being there. That's death. This tag includes post about the death of particular people, or about death in general.
Cryonicists use the concept of information-theoretic death, which is what happens when the information needed to reconstruct you even in principle is no longer present. Anything less, to them, is just a flesh wound.