This paper presents the failure analysis of a 1000 US gallon, horizontal, propane tank, which suddenly circumferentially separated at its central section while being radiantly heated. Thermo-hydraulic analyses of the tank and its contents, as well as nite element analysis of its possible thermal stress states coupled with other evidence show that the reasons for the catastrophe were complex-weld defects, low melting point ttings, placement, and re ghting-and all contributed to the failure. Recommendations are made in order to prevent future similar accidents.