Something common characterizes the Book of Genesis, the ancient Vedantic writings, the Indo-Aryan tales of the Mahabharata, the end of days and the great war of "fire mushrooms," even the Norse tales of Ragnarok.
We always find the last straw that finally unleashed God's wrath was the attempt by mankind to corrupt the original seed of man, made in the image of God, by mixing it with demons and beasts to produce abominations.
God produced the Flood to counter the genetic miscreants produced by the union of Nephilim and human women. The Mahabarata says that Vishnu struck down the world of man because he was intent on mixing his seed with that of beasts. The Vedantic writings say that men were seeking to merge their descendant lines with that of evil spirits and imps from the netherworld into something which would be unable to attain the divine.
In all these writings there is the same consistent theme found each and every time - man is a special and unique creation who is a child of God and when he grew so wicked he sought to pervert his genetic inheritance, the creator moved to close the curtain on that era. God intervenes to prevent human beings from moving themselves so far from his original design they can no longer be considered human and therefore beyond salvation.
In all these ancient books, such efforts by the children of evil are cut short when heaven ends the cycle of life with a great and terrible Ragnarok.
You can laugh all you want at these ancient writings, except that these very same books say in the last days men always scoff at wisdom and reject the lessons of history. So they predicted that as well. Most of the ancient texts seem to know in advance what human beings will do when the end approaches better than most men themselves do.