Arduous Duty: Using Three Data Sources to Create a Single Wildland Fire Fighter On-Duty Death Surveillance System

Posted on by CDR Christa Hale, LCDR Corey Butler, and Elizabeth Dalsey, M.A.


Wildland fire fighters are required to pass an “arduous duty” physical fitness test annually to help ensure that they are prepared for the physical nature of the job. Unlike structural fire fighting, wildland fire fighting often requires long work shifts that may last up to 14 continuous days, and often takes place in environments that are challenging with regard to temperature and terrain. Because of this difference, researchers cannot assume that study findings among structural fire fighters would apply to wildland fire fighters. Because wildland fire fighter-specific fatality data are often sparse or combined with information on all U.S. fire fighter deaths, NIOSH researchers had trouble answering our partners’ most basic on-duty fatality questions such as:


  • What injuries are killing wildland fire fighters on the job?
  • How many wildland fire fighters are dying from cardiac events on the job?
  • Why do different agencies report different numbers of fatalities per year? and
  • What can we do to prevent on-duty deaths?

These types of questions led the NIOSH Wildland Fire Program to create a surveillance system to track wildland fire fighter fatalities in the U.S., which proved to be an “arduous duty” of its own.

Creating the NIOSH Wildland Fire Fighter On-Duty Death Surveillance System

To develop NIOSH’s Wildland Fire Fighter On-Duty Death Surveillance System, our researchers identified three data sources that track on-duty wildland fire fighter fatalities and provide the types of data needed for this occupational health surveillance effort:

  • The National Fire Protection Association (NFPA) Fire Incident Data Organization,
  • The National Wildland Fire Coordinating Group (NWCG) Safety Gram, and
  • The United States Fire Administration (USFA) fire fighter fatality data system.

So, why didn’t we just use one of these sources if they all track wildland fire fighter fatalities? Each of the three data sources has different criteria for inclusion in their system and thus, does not necessarily identify all wildland fire fighter fatalities. Even though it seemed like they were tracking the same thing, they were including cases based on slightly different criteria, making it difficult to know the true number of fatalities. To overcome this limitation, we determine which cases are included in our system by using a consistent case definition. Case definitions contain uniform sets of criteria about the events to be included in the system, so that each person applying the definition to a case can classify it correctly and make a consistent decision about including it or not. By consistently applying a case definition, we feel more confident that the number of fatalities that happen in one year is comparable to the next year because we are counting the same thing.

The process for developing this surveillance system and keeping it up to date by using three data sources can be challenging and time consuming for several reasons. First, the data sources do not collect the same level of detail. For example, USFA collects up to 233 pieces of information for each fatality while NWCG collects nine. Second, the data are released at different intervals as some data sources report in almost real-time while others do not report until several years after the event. Finally, for some cases reported in multiple data sources, information such as the exact date or locations of death differs making it difficult to match up cases between data sources. Thus, to confirm cases and ensure the information collected is accurate, we have to reach out to the agencies that collected the data as well as other sources to determine whether a reported fatality was truly unique or actually contained within more than one data source.

For our surveillance system, we applied the following case definition, which we ultimately recommended as a common case definition for on-duty wildland fire fighter fatalities1:

  • Any fatal injury or illness (e.g. sudden cardiac or cerebrovascular event) sustained among wildland fire fighters while on-duty at a wildland fire-related event or while performing wildland fire duties in the U.S.
  • “Wildland fire” refers to a non-structure fire occurring in vegetation or natural fuels and includes prescribed fire and wildfire.
  • ‘Wildland fire fighter’ refers to a person whose principal function is fire suppression (includes paid/career and volunteer workers).

“On-duty” refers to:

  • a wildland fire or nonfire activity;
  • responding to or returning from a wildland fire;
  • performing other officially assigned wildland fire or wildland fire fighter duties, such as reconnaissance, physical fitness training, maintenance, public education, or investigations;
  • being on call, under orders, or on standby duty, except at the individual’s home or other place of business; and
  • events covered under the Hometown Heroes Survivors’ Benefits Act of 2003.

Fatalities that would be excluded would be those involving non-fire personnel (e.g., law enforcement officers), those occurring in U.S. territories and overseas military installations, commutes to/from work, and recreational activities not required by the department/agency.

Findings from the NIOSH Wildland Fire Fighter On-Duty Death Surveillance System

The NIOSH Wildland Fire Fighter On-Duty Death Surveillance System captured 247 unique deaths from the three data sources that occurred between 2001 and 2012. When comparing the fatalities across the three data sources, only 73% (181) of fatalities were identified within all three. Thirteen percent (31) were identified in two sources and 14% (35) were identified in only one source. Because no one data source captures all unique deaths, it is necessary for NIOSH researchers to use the data from all three data sources to truly understand the number and the types of deaths captured within each data source.

For 2001 to 2012, USFA provided the largest number of fatalities (223), followed by NWCG (210) and NFPA (207). Why the differences between the data? All three data sources report on-scene fatalities fairly consistently, especially those associated with a traumatic injury at a wildland fire. However, the data sources differ in what they consider an on-duty death. NWCG primarily captures what are known as “line of duty deaths” or deaths that occur while engaged in specific on-the-job wildland fire response and training duties. USFA and NFPA, on the other hand, not only include line of duty deaths but also those fatalities that occurred in situations where fire fighters were not actively fighting a fire or training, but were still considered on duty (such as when traveling to or from the fire, off duty but still in mobilization status, or performing other duties at the fire station).

The data sources also differ in who they include in their fatality tracking systems. For example, while NFPA and USFA only collect information on fire fighters, NWCG also includes some fatalities among non-fire-related emergency response personnel (such as law enforcement officers) that were fatally injured at a wildland fire. Because NWCG reports the least amount of detail, we sometimes need to collect additional information to confirm that the person who died was a fire fighter.

Another difference is related to the case definitions that the data sources use. USFA includes medically-related wildland fire fighter fatalities (such as heart attacks and strokes) that occurred within 24 hours of a non-routine, physically stressful or strenuous emergency response activity, even if the decedent was off duty, as dictated by the Hometown Heroes Survivors’ Benefit Act of 2003*. NWCG and NFPA typically do not include these types of events and only included medically-related events if the death occurred while on-duty. There were at least 10 fatalities that were found only in USFA as a result of the Hometown Heroes classification.

Moving Forward

So, how do we overcome these challenges? There is an overall push in occupational health (and public health practice in general) to standardize the way that information is collected and reported to reduce the resources needed to perform occupational health surveillance. In this case, use of a common case definition among the three data sources would reduce the amount of time spent comparing the data and seeking additional information to prevent misclassification.

We recognize that the purpose of data collection among these data sources is not primarily for occupational health practice and thus, a common case definition might not be practical. In that case, we recommend that the sources provide more complete descriptions of events. With more information, researchers can appropriately classify wildland fire fighter fatalities to ensure that fatalities related to wildland fires can be described correctly. In addition, agencies collecting these data should consider providing more detailed information on their inclusion criteria when reporting their findings. This additional detail would reduce confusion among the public and media regarding why each data source is reporting different annual totals.

Occupational health practitioners often rely on non-public health data sources to perform occupational health surveillance. As you can see, something as seemingly simple as on-duty wildland fire fighter fatality surveillance can be very complex. We recommend use of a common case definition to help characterize all on-duty wildland fire fighter deaths in a more timely and accurate manner to assist with defining the true occupational fatality burden.

To learn more about the findings of the NIOSH Wildland Fire Program Wildland Fire Fighter On-Duty Death Surveillance system see the recent article in the Journal of Occupational and Environmental Hygiene.

CDR Christa Hale is a Commander with the United States Public Health Service and Senior Epidemiologist and Veterinarian in the NIOSH Western States Division.

LCDR Corey Butler is a Lieutenant Commander with the United States Public Health Service and an Occupational Safety and Health Specialist in the NIOSH Western States Office. LCDR Butler coordinates the NIOSH Wildland Firefighting Program.

Elizabeth Dalsey, M.A., is a Health Communication Specialist in the Western States Division. Ms. Dalsey also coordinates NIOSH’s American Indian/Alaskan Native Initiative.

*The Hometown Heroes Survivors’ Benefit Act of 2003 is a bill meant to ensure that a public safety officer who suffers a fatal heart attack or stroke while on duty shall be presumed to have died in the line of duty for purposes of public safety officer survivor benefits. For more information, see:


  1. Butler C, Marsh S, Domitrovich J, Helmkamp J [2016]. Wildland fire fighter deaths in the United States: a comparison of existing surveillance systems. J Occup Environ Health, Advance online publication. Accessed 2016 Dec 23.
Posted on by CDR Christa Hale, LCDR Corey Butler, and Elizabeth Dalsey, M.A.

2 comments on “Arduous Duty: Using Three Data Sources to Create a Single Wildland Fire Fighter On-Duty Death Surveillance System”

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    I cannot access the full article, but I would like to offer some clarifications in case they are not fleshed out in the full article. By rule, federal arduous firefighters can actually work up to 21 continuous days and often do. Also, not all wildland firefighters are arduous pack-tested, but often do similar work. Some state agencies that fight wildland fires require only the moderate pack test for in-state assignments. Many volunteers that fight fires in their own response areas may have no fitness requirements at all. These points could be especially important if you are investigating cardiac events. Many people have died taking the arduous pack test as well.

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Page last reviewed: April 13, 2021
Page last updated: April 13, 2021