This paper summarises a study conducted by Virginia Tech for the American Lifelines Alliance (ALA) in 2005 to document interdependencies and impacts among utilities and transportation systems (lifelines) associated with the 2004 hurricane season in Florida. The greater Orange County, Florida area was chosen as the study area for the investigation, which focused primarily on the experience of owners and operators of electric power systems, water and wastewater utilities, natural gas and petroleum fuel systems, and communications and transportation networks. Key personnel from utility and transportation organisations were interviewed by the study team to help identify lifeline interdependency issues that affected the ability of lifeline owners and operators to provide continued service to customers. Detailed information was collected on interdependent lifeline performance and lessons learned from the impacts of multiple hurricanes that could provide the basis for developing improved guidance for hazard mitigation and lifeline service restoration.