Humanity as we know it now, ends by the flu. Sentient organic life on earth, by either flu or nuclear war. The earth itself... by being eaten by the sun when the sun enters a new phase of it's "life" as a star.
The universe.... the big squish.
"If force is the game, the murderer wins over the pickpocket." Ayn Rand
"Justice is the midpoint between being treated unjustly, and treating others unjustly." Aristotle