Apocalypse

[Maid]

Even if nuclear war happens of major proportions, some will still survive. Don't underestimate humans. If something does end humans all together it would have to be something all encompassing. Like a large object falling on earth, some sort of disease that can wipe all humans and spread easily(likeliness of such indiscriminate and easy to transfer disease are as likely as something falling on our planet and obliterating it).