Cahokia Mounds State Historic Site (IMAGE) Washington University in St. Louis Caption Archaeologists at Washington University in St. Louis found scant evidence that 'wood overuse' at Cahokia caused local flooding and subsequent collapse. Credit Joe Angeles / Washington University Usage Restrictions For editorial purposes License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.