A computer based fire model, Fire Dynamic Simulator was used to reconstruction a portion of a fire that occurred in the basement of a hardware store. A FDS model scenario was deveoped that represented the building geometry, material thermal properties, and fire behavior based on inforamtion and photographs from investigations by the Fire Department of New York and the Bureau of Alcohol, Tobacco, and Firearms. The FDS calculations that best represent the reported fire conditions indicate that a fire between 500 kW and 2000 kW originating near the rear basement door of the hardware store would have generated temperatures sufficient to cause the fusible link to release the fire door in less than 130 s.