There is a body of scientific evidence that a massive event occurred then. The Worldwide lore of the flood may very well be based on this event. There is evidence that what was likely a breaking up comet struck the earth in a glazing manner in the Northern Hemisphere. There are multiple craters along the Southeast Coast of the United States, one massive crater in Greenland (which could easily have caused a massive ocean level change all over the planet) and signs of impacts all over southern Europe and the middle east. The sudden mini Ice Age called the Younger Dryas happened. There are a number of major articles on the internet about this. (The Younger Dryas impact hypothesis (YDIH) or Clovis comet hypothesis posits that fragments of a large (more than 4 kilometers in diameter), disintegrating asteroid or comet struck North America, South America, Europe, and western Asia around 12,850 years ago, coinciding with the beginning of the Younger Dryas cooling. (ref. Wiki article – https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesis)
There is a large amount of lore that speaks of humans going underground during those times. Many researchers, including myself, feel that that is the reason for so many underground bases around the world.