http://news.yahoo.com/huge-ancient-civilization-collapse-explained-123449804.html
Huge Ancient Civilization's Collapse Explained
By Charles Choi, LiveScience Contributor | LiveScience.com
The mysterious fall of the largest of the world's earliest urban
civilizations nearly 4,000 years ago in what is now India, Pakistan,
Nepal and Bangladesh now appears to have a key culprit - ancient
climate change, researchers say.
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