Comet wiped out northern hemisphere 13K years ago

Vague stories of apocalyptic events, fire and brimstone, great floods, etc. These are common long distant past historical themes running through many physically seperated cultures.

Traditionally they've been chalked up as legends, fanciful stories, or gross exaggerations...well maybe they all had a basis in actual events.

[...]Stone Age cultures were destroyed and populations of mammoths and other large land animals were wiped out. The blast also caused a major bout of climatic cooling that lasted 1000 years and seriously disrupted the development of the early human civilizations emerging in Europe and Asia.

"This comet set off a shock wave that changed Earth profoundly," said Arizona geophysicist Allen West.

"It was about 2km-3km in diameter and broke up just before impact, setting off a series of explosions, each the equivalent of an atomic bomb blast.

"The result would have been hell on Earth. Most of the Northern Hemisphere would have been left on fire."[...]

UPDATE: Some background on the mass die off 13K years ago -- as far back as 03' this Science Daily article suggested it was a major climate change event that caused the die offs.