Rocks fall, everyone dies
"Rocks fall, everyone dies" is a method of ending a campaign commonly used by angry DMs who have gotten fed up with their players' bullshit. In this situation, the characters are arbitrarily killed by some unavoidable fate such as an avalanche or a cave-in (the titular rocks falling) and the DM declares this the end of the game.
This was used in the ending of the NWN2 original campaign. And at the beginning of the first Icewind Dale game, killing everyone that isn't the player party. In theory, this may have been inspired by Tomb of Horrors, in which entering the wrong room CAN lead to "Rocks Fall" everyone dies...if you don't leave within 10 seconds.
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The original appearance of the "Rocks fall" phrase, according to Twenty Sided Blog.