posted on Mar, 8 2013 @ 05:58 PM
Relatively large land mass and islands along the Mid-Atlantic Ridge where the Azores are now.
Relatively advanced civilization with laws, agriculture, seafaring, etc. (No lasers or space ships.)
Comet impact at the beginning of Younger Dryas. (Didn't help)
Massive earthquakes drop the land down into the sea, with tsunamis driven inland from all sides.
A few scattered survivors.
Thousands of years to lose or confuse the story.