1. Asteroid.
2. Global Warming.
3. Great Flood.
4. Lack of Regulation.
Native global flood stories are documented as history or legend in almost every region on earth. Old world missionaries reported their amazement at finding remote tribes already possessing legends with tremendous similarities to the Bible’s accounts of the worldwide flood. H.S. Bellamy in Moons, Myths and Men estimates that altogether there are over 500 Flood legends worldwide. Ancient civilizations such as (China, Babylonia, Wales, Russia, India, America, Hawaii, Scandinavia, Sumatra, Peru, and Polynesia) all have their own versions of a giant flood.
For more, plus very interesting table (a little further down), see:
http://www.nwcreation.net/noahlegends.html