Causal attribution for one of the largest disasters in American history has undergone three major shifts. From August 2005 through November 2009, the principal explanation of the flooding of New Orleans was characterized by three distinguishable phases - reactive, organizational, and legal - as the catastrophic events of Hurricane Katrina were ascribed to natural, geotechnical, and environmental causes. From a monstrous storm, to failed levees, and ultimately the loss of wetlands through an insidious shipping channel, 'what happened' should be viewed as a technoscientific development in which media and litigation processes transformed the structural conditions for the production of knowledge claims. Video ethnography is used to examine causal transitions as structural conditions of inquiry changed. Levees - the most important symbol of failure - shifted from cause to consequence. Understanding of disaster cycled from nature to humans, and to nature once more.