So it turns out that it's possible that a meteorite impact occurred here in North America 13,000 years ago, when the place was still largely covered in ice. The impact may have wiped out all of the major animal species on the continent through chaotic climate change. It may also have wiped out the predominant civilization. Geologically speaking, 13,000 years ago is absolutely nothing.
Shows how fragile things can be. And by things I mean all of the critical things upon which we survive.