Let's put this to rest: no such cheat exists in GTA San Andreas. The game's cheat codes modify weather, spawn vehicles, grant weapons, alter wanted levels, and change pedestrian behavior—but none trigger an apocalyptic event or "end the world" in any literal sense.
If you're looking for mayhem, these codes create plenty of chaos without ending the game world:
DOWN, LEFT, UP, LEFT, X, R2, R1, L2, L1 (PS2)DOWN, UP, UP, UP, X, R2, R1, L2, L2L1, R1, L2, R2, LEFT, RIGHT, LEFT, RIGHTR2, X, L1, L1, L2, L2, L2, TRIANGLEThese create entertaining pandemonium but don't destroy the game world. Use them responsibly in a separate save file to avoid unintended consequences.