Despite the wanton destruction during the past 200 years, some outstanding sites have been saved in Louisiana,1 Mississippi,2 Alabama,3 Tennessee,4 I… - Graham Hancock

The fullest account we have of Oannes is found in surviving fragments of the works of a Babylonian priest called Berossos who wrote in the third century BC. [...] Oannes did not do his work alone but was supposedly the leader of a group of beings known as the Seven Apkallu — the "Seven Sages" — who were said to have lived "before the flood" (a cataclysmic global deluge features prominently in many Mesopotamian traditions, including those of Sumer, Akkad, Assyria and Babylon). Alongside Oannes, these sages are portrayed as bringers of civilization who, in the most ancient past, gave humanity a moral code, arts, crafts and agriculture and taught them architectural, building and engineering skills.

An Ojibwa tradition seems relevant. It speaks of a comet that 'burned up the earth' in the remote past and that is destined to return:
'The star with the long, wide tail is going to destroy the world some day when it comes low again. That's the comet called Long-Tailed Heavenly Climbing Star. It came down here once, thousands of years ago. Just like the sun. It had radiation and burning heat in its tail ...
Indian people were here before that happened, living on the earth. But things were wrong with nature on the earth, and a lot of people had abandoned the spiritual path. The Holy Spirit warned them a long time before the comet came. Medicine men told everyone to prepare. ... The comet burnt everything to the ground. There wasn't a thing left ...
There is a prophecy that the comet will destroy the earth again. But it's a restoration. The greatest blessing this island [Turtle Island/America] will ever have. People don't listen to their spiritual guidance today. There will be signs in the sun, moon and stars when the comet comes down again.

Eight thousand years is a very long time but