This thesis is an investigation of FEMA and its use of the vulnerability approach towards disaster management between the years 1993 and 2001 during the 'Wilt revolution'. This thesis will show that the vulnerability approach used by Witt as part of his 'all-hazard' approach and mitigation strategies resulted in FEMA's successes during this time frame. The Witt era was set apart from the rest of FEMA history, which was defined by continuous failure. An examination of four different cases, Hurricane Andrew, the Oklahoma City Bombing, September 11th and Hurricane Katrina, will be undertaken and analysed within the context of four organizational factors which influence behaviour: The four categories, goal displacement, organizational structure, leadership and learning, will frame the cases and show how the vulnerability approach was present during the successes of the Witt revolution.