In the Emberverse Series, the equivalent to the Event was the Change, which was probably caused by the Event.
The Event was, from outward appearances, a storm over Nantucket Island. When it was over, the stars were in the wrong position in the sky and the moon was in the wrong phase, although the sun rose on schedule. The inhabitants of the island and the crew of the USCGC Eagle which was sailing nearby, found that the island and its contiguous waters in the shape of an ellipse centered on the island had moved to the year 1250 BCE. The nearby mainland which had been part of the United States of America, was undeveloped and inhabited by proto-Indians whose primary hunting weapon was the spear.