World ending events.

The Rumbling (Attack On Titan): All the walls of Paradis Island crumbled down and have unleashed the Colossal Titans within by the powers of the Founding Titan, used by Eren.

Convergence Event (Dead Space): Once enough dead bodies/matter is gathered, the Marker flies to the sky and starts gathering all Necromorphs/corpses, whilst also dragging a chunk of the host planet with it; resulting in the birth of a Brethren Moon.

Faro Plague (Horizon Zero Dawn): Thanks to the hubris and ego of a billionaire, the machines that once helped humanity turned against them due to a glitch in the system, causing them to consume any organic material and render Earth uninhabitable for many years to come.