A review of the search for causes of accidents shows a pronounced trend. Whereas technology and equipment constituted the dominant cause in the 1960s and organisation was hardly represented at all, in the mid-1990s human performance had taken over as the dominant cause by far, while technology and equipment had dropped significantly as an attributed cause, and organisation continued a slow but evident increase. In the sequential accident model the root cause is looked for by searching backwards in the causal chain until the ‘first domino’ is identified. While the sequential model assumes a simple linear chain of events, the chain of events in the epidemiological accident model assumes a complex linear relationship. Rosness et al. apply a different classification in their treatment of organisational accidents. Their review of the different understandings of accidents and safety focuses on generic models of the genealogy of accidents and how they are handled.