A fire destroyed three tanks containing crude sulfate turpentine (CST) at a storage facility in Savannah, Georgia, on April 10 1995 prompting an evacuation, and resulting in some environmental damage The events of this fire have been documented an a US EPA report[1] The investigators deter mined the most likely cause of ignition was overheating in a newly-installed activated-carbon drum as air was drawn in during evening cooling One aspect not entirely explained in the EPA report is that the tanks were connected by a vapor manifold and were not protected by detonation arresters yet the flames initially propagated to only one tank This paper discusses the development of a model to quantify the likely sequence of events that is consistent with observations Tank inflows and outflows forced by the diurnal temperature cycle were modeled to calculate hydrocarbon concentrations in the vapor space This establishes that the combination of vapor concentrations above the lower flammable limit and oxygen concentrations above the lower limit to support combustion, occur for only a few hours during the day Further estimates of the ignition, flame acceleration, and run up distance indicate that an explosion probably occurred inside the polyvinyl chloride (PVC)pipe The forces from such an explosion would be sufficient to open the PVC pipe thereby slowing the flame front propagation and contributing to the failure to initially ignite more than one tank This paper illustrates bow modeling strengthens an accident investigation and helps distinguish between alternative postulated ignition sequences.