On 25 September, 1998, an explosion occurred at an Esso gas plant at Longford, near Melbourne, which killed two men and interrupted the gas supply to the state of Victoria for two weeks. Because of the economic cost of this disruption the state government set up a Royal Commission - the most powerful inquiry possible. The inquiry uncovered an intricate causal network, ranging from front line operator error right back to company and even government policy. This paper will outline the causal network by providing an AcciMap of the incident (Rasmussen, 1997). A number of features of the map will be explained in the next sections. The paper will then examine the strategies of causal explanation used by the parties represented at the inquiry.