On May 30, 1999 a fire in a townhouse at 3146 Cherry Road NE, Washington D.C. claimed the lives of two District of Columbia firefighters and burned other firefighters. The District of Columbia Fire and Emergency Medical Services Department Reconstruction Committee requested the assistance of NIST for the purpose of examining the fire dynamics of this incident.
NIST has performed computer simulations of the fire using the NIST Fire Dynamics Simulator (FDS) and Smokeview, a visualization tool, to provide insight on the fire development and thermal conditions that may have existed in the townhouse during the fire. This document describes the input and the results of the NIST FDS calculations.
The report, "Simulation of the Dynamics of the Fire at 3146 Cherry Road NE Washington D.C., May 30, 1999 (NIST IR 6510)," describes the results of calculations using the NIST FDS that were performed to provide insight on the thermal conditions that may have occurred during the fire. Input to the computer model was developed from 3 sources; the District of Columbia Fire and Emergency Medical Services Department Reconstruction Committee, photographs and measurements taken by NIST staff during a June 3, 1999 site visit, and from material properties taken from the FDS database. An FDS model scenario was developed that best represented the actual building geometry, material thermal properties, and fire behavior based on information from the Reconstruction Committee and physical evidence. The results from this model scenario are provided with the report. Results from an additional model scenario, which included the opening of the sliding glass door on the first floor prior to opening of the sliding glass door in the basement, are also presented.
The FDS calculations that best represent the reported fire conditions indicate that the opening of the basement sliding glass doors provided outside air (oxygen) to a pre-heated, under ventilated fire compartment, which then developed into a post-flashover fire within 60 seconds. Some of the resulting fire gases flowed up the basement stairwell with high velocity and collected in a pre-heated, oxygen depleted first floor living room with limited ventilation.