During the investigation the investigator may have only one opportunity to document a fire scene. This article is intended to provide methods and procedures that will assis thte on-scene investigator to efficiently obtain the information necessary to do computer modeling for the scene at a later date.

Personnel at MDE have been modeling fire for many years and have been involved with the development of the modeling software leading to the current version of Fire Dynamic Simulations (FDS). With the introduction of FDS there has been an increased utilization of fire models in the process of fire investigation and subsequent litigation. The current version of FDS provided by NIST is well documented in providing data on a timeline to reach tenability limits or when an environment becomes un-survivable to an occupant. These models may be used in the verification of an investigators' hypothesis or theory of a fire progression. In the event that there has been a fatality or severe injury, it is almost essential to take these measurements.

In any given fire scene it may not be clear if modeling will be necessary during the first aspects of fire investigation. It is prudent to obtain the basic information first, and if time and resources allow, collect more detailed information. Note that some structures have "as-built" drawings; if available, the investigator should take time to verify that the prints are representative of the structure.