Hurricane Katrina hit Louisiana on early Monday morning, August 29, 2005, and by Monday night levees and flood walls were bursting across New Orleans. Since then, four teams have investigated what happened.

The American Society of Civil Engineers (ASCE) inspection team was led by Peter G. Nicholson, a civil and environmental engineer at the University of Hawaii at Manoa. In his November 2 testimony to the U.S. Senate, Nicholson said his group observed "a number of different failure mechanisms" that led to "dozens of breaches" throughout the levee system.