[TXnMA]

Have you a better explanation?

[onedoug]

...forest fires broke out across the continent, sending up a thick layer of soot and dust that blocked out the sun. A sudden ice age ensued, and some of the Earth's largest animals went extinct in a blink of geological time.

Not necessarily. I just think it odd that 4,000+ years later these same types of animals were still around LA despite what this article suggests above. It doesn't seem to make sense overall.