Post a way you die, and the next user posts a way to save you and a way for him to die, etc. etc.
E.G.
Guy 1: I save you by bringing a water tsunami and dousing the flames.
I fall into a pit of spikes.
Guy 2: I use a time machine and take you back before you fell.
I drown in glue.
TO START:
I swallow a bomb shaped like a mint.