[js1138]

The few survivors would pass it down as oral tradition. And if your whole world is devastated, far as far as you can see or travel, you probably assume it wasn't local.

You'd have the same effect if it was local. Occam's Razor.

[Celtjew Libertarian]

You'd have the same effect if it was local. Occam's Razor.

But I don't think you'd have quite the consistency across legends.

Besides, one huge disaster is fewer "entities" if you will than many small ones.