Building is burned after the fire incident analysis

Journal Article Reports on Fire Dynamics Simulator Modeling of a Line-of-Duty Death

June 7, 2024

A new peer-reviewed journal article on using Fire Dynamics Simulator (FDS) to model a line-of-duty death (LODD) has been published in the Journal of Fire Sciences. The paper was authored by Jason Floyd and Dan Madrzykowski from the Fire Safety Research Institute (FSRI), part of UL Research Institutes, as part of the Fire Incident Analysis research project. This paper was published in the journal’s four-paper Special Issue series that continued research on a LODD that occurred in 2005 after an instructor collapsed at a fire training facility in Pennsylvania.

This study aimed to reconstruct the fire incident by using state-of-the-art computer fire modeling, namely the most recent edition of FDS with a recently developed engineering pyrolysis model referred to as SBPyro in the FDS User’s Guide. This research serves as a case study for using fire modeling as an aid to investigating LODDs and line-of-duty incidents. It also highlights how FSRI research contributes to improvement in modeling application and methodology.

To carry out this project, researchers first applied the findings from the other three papers in the special issue series. The applications of the other papers are as follows:

  1. Predicting fire growth and response of protective gear: The first paper discusses the new materials and products database, which fire modelers can use to predict material performance, including the pyrolysis of materials. Data collected during this research was used for the prediction of fire growth and the response of firefighter protective gear (in this case, the self-contained breathing apparatus (SCBA) facepiece).
  2. Assessing thermal exposure conditions: The second paper describes the thermal exposures encountered by firefighters on the fireground and proposes to expand the classification of those exposures into hazard categories. These categories were used in the fire reconstruction for assessing the exposure conditions during the incident.
  3. Characterizing the SCBA facepiece performance: The third paper evaluates the thermal performance of the SCBA facepiece under intense heat. Data from this paper and other work was used to develop criteria for the expected time of hole formation in a facepiece exposed to a fire environment. 


The findings from these papers, in conjunction with several recent developments in fire models, demonstrate that the model results:

  • Show the promise of using the heat flux scaling method to more accurately predict the burning rate. 
  • Show that FDS can forecast how exposure changes in the burn room over a multi-hour, multi-evolution training. 
  • Demonstrate the potential of assessing areas where there is no fire damage based on its prediction of wall temperatures. 
  • Confirm the findings of the National Institute for Occupational Safety and Health investigation that the nature of the below-grade burn room and the procedures used resulted in a risky environment and prolonged exposure for the instructor. 
  • Demonstrate that the newer facepiece models provided significantly more margin of safety at emergency levels of exposure. 
  • Indicate that an SCBA facepiece compliant with the most recent NFPA 1981 standard would have avoided the incident if the direct cause of the instructor’s collapse had been the facepiece failure.*

*More research is needed to be certain about this conclusion

“The work demonstrates how fire modeling can be used to combine multiple avenues of research into the analysis of a complex fire event, providing insights that would otherwise be difficult to achieve via other means.” Jason Floyd, Lead Research Engineer, FSRI

About the Journal of Fire Sciences:

The Journal of Fire Sciences is a leading, peer-reviewed international journal for the reporting of new and significant fundamental and applied research within the fire safety science community. Its overall content is generally aimed toward the prevention and mitigation of the adverse effects of fires involving combustible materials.