Cataclysm

The Cataclysm was the instant in which the Wanderer, having been granted infinite power by the gods, shattered the infinitely large Worldplane with a single blow.

This event took place across an infinite amount of time, and is therefore always still in the process of happening somewhere.

This infinite time interval is what separates the time of Wë from the time of La.

Other timelines had their own versions of the Cataclysm, with only the causes being different, such as the different confrontations between the Wanderer and evolved forms of Surtur, or the prophesized appearance of an earth/matter elemental. It's currently unclear whether all of these lead to the same Broken World, or if there are just as many alternate versions of that setting.