Attempting to redefine the common denominators of tragedy fires

“A Classification of US Wildland Firefighter Entrapments Based on Coincident Fuels, Weather, and Topography”

Above: Figure 1 from the research paper. Distribution of 166 US wildland firefighter entrapments that occurred within CONUS (1981–2017) by time of day (local time) and month of the year.

On October 9, 2019 a document was published that summarized the work of four researchers who sought to find commonalities that led to the entrapments of firefighters on wildland fires. The paper is titled, “A Classification of US Wildland Firefighter Entrapments Based on Coincident Fuels, Weather, and Topography.” Apparently they were hoping to confirm, fine tune, revise, or update the “Common Denominators of Fire Behavior on Tragedy Fires” defined by Carl C. Wilson after the 1976 Battlement Creek Fire where three firefighters were killed near Parachute, Colorado.

Mr. Wilson developed two lists, one with four items and another with five. Here is the five-item list:

  1. Most of the incidents occurred on relatively small fires or isolated sectors of larger fires.
  2. Most of the fires were innocent in appearance prior to the “flare-ups” or “blow-ups”. In some cases, the fatalities occurred in the mop-up stage.
  3. Flare-ups occurred in deceptively light fuels.
  4. Fires ran uphill in chimneys, gullies, or on steep slopes.
  5. Suppression tools, such as helicopters or air tankers, can adversely modify fire behavior. (Helicopter and air tanker vortices have been known to cause flare-ups.)”

The four more recent researchers conducted an analysis of the environmental conditions at the times and locations of 166 firefighter entrapments involving 1,202 people and 117 fatalities that occurred between 1981 and 2017 in the conterminous United States. They identified one characteristic that was common for 91 percent of the entrapments — high fire danger — specifically, when the Energy Release Component and Burning Index are both above their historical 80th percentile.

They also generated an update of the time of day the entrapments occurred as seen in the figure at the top of this article. This has been done before, but it’s worthwhile to get an update. And, this version includes the month.

You can read the entire open access article here. If you’re thinking of quickly skimming it, the 7,000 words and the dozens of abbreviations and acronyms make that a challenge. There is no appendix which lists and defines the abbreviations and acronyms.

The authors of the paper are Wesley G. Page, Patrick H. Freeborn, Bret W. Butler, and W. Matt Jolly.

Below are excerpts from their research:

…Given the findings of this study and previously published firefighter safety guidelines, we have identified a few key practical implications for wildland firefighters:

  1. The fire environment conditions or subsequent fire behavior, particularly rate of spread, at the time of the entrapment does not need to be extreme or unusual for an entrapment to occur; it only needs to be unexpected in the sense that the firefighters involved did not anticipate or could not adapt to the observed fire behavior in enough time to reach an adequate safety zone;
  2. The site and regional-specific environmental conditions at the time and location of the entrapment are important; in other words, the set of environmental conditions common to firefighter entrapments in one region do not necessarily translate to other locations;
  3. As noted by several authors, human factors or human behavior are a critical component of firefighter entrapments, so much so that while an analysis of the common environmental conditions associated with entrapments will yield a better understanding of the conditions that increase the likelihood of an entrapment, it will not produce models or define characteristics that predict where and when entrapments are likely to occur.


The one characteristic that was common for the majority of entrapments (~91%) was high fire danger. As a general guideline, regardless of location, the data suggest that entrapment potential is highest when the fire danger indices (ERC’ and BI’) are both above their historical 80th percentile. Until recently, spatially-explicit information on fire danger has not been widely available as most firefighters have relied on fire danger information available at specific weather stations, which are often summarized into Pocket Cards [83]. Fortunately, fire danger forecasts across CONUS are now available in a mobile-friendly format (see that can be displayed spatially for each of the fire danger indices separately or combined into a Severe Fire Danger Index.



The times and locations where wildland firefighter entrapments occur in the US cover a wide range of conditions. Current firefighter safety guidelines seem to emphasize only a subset of the possible conditions due to a focus on the factors that maximize the potential for extreme fire behavior. While many of these safety guidelines are still intuitively valid, caution should be exercised during relevant firefighter training so as to not ignore or undermine the fact that entrapments and fatalities are possible under a much wider range of conditions.

Despite the wide range of environmental conditions associated with entrapments, we have shown that it is possible to identify unique combinations of environmental variables to define similarities among groups of entrapments, but these will necessarily be context and site specific. For most entrapments, the only common environmental condition was high fire danger, as represented by fire danger indices that have been normalized to represent the historical percentile at a particular location. As such, at large spatial scales, fire danger and its association with fire weather should continue to be monitored and reported to firefighters using both traditional methods (i.e., morning fire weather forecasts) and also newer methods that take advantage of advancements in mobile technology.

Goal-oriented decision-making

Goal-oriented training can change the balance between reflective and reflexive processes.

Emergency responders have all been there — they rush to get to an incident, very quickly size it up, and take action. But award-winning research looks at incident managers that include a third step, actually formulating a plan of action. It has been argued that the development of explicit plans enables shared situational awareness and goals to support a common operating picture.

An article written by Dr. Sabrina Cohen-Hatton and R.C. Honey, Goal-Oriented Training Affects Decision-Making Processes in Virtual and Simulated Fire and Rescue Environments, received the Best Paper of the Year Award from the Journal of Experimental Psychology: Applied in 2016.

The research evaluated 48 incident commanders from 11 Fire and Rescue Services in the United Kingdom who had just received one-hour of training on incident management. They were divided into two groups, one with standard training and the other that included information about decision-making:

For Group Decision, slides were included that highlighted the use decision controls, which involved using a rapid mental check list of questions at key decision points: Why am I doing this (i.e., what are my goals)? What do I expect to happen (i.e., what are the anticipated consequences)? and Are the benefits worth the risks? When participants given goal-oriented training watched the footage, and were asked what actions they would take next, they were directed to answer with reference to the decision controls.

After the brief training the firefighters participated in immersive virtual reality (VR) simulations of a house fire, a traffic collision, and a “skip fire that spreads to an adjoining shop”.

The results showed that goal-oriented training affects the decision-making process in experienced incident commanders across a variety of simulated environments
ranging from immersive VR through to live burns. There is evidence that the training can change the balance between reflective and reflexive processes which could have the potential to increase the effectiveness of communication between members of firefighting crews and to improve

Adding to the list of common denominators of tragedy fires

More common denominators of tragedy fires.

(Photo: Happy Camp Complex, 2014, by Kari Greer.)

About forty years ago Carl Wilson, one of the early wildland fire researchers, developed his list of four “Common Denominators of Fire Behavior on Tragedy Fires”, that is, fatal and near-fatal fires.Carl Wilson

  1. Relatively small fires or deceptively quiet areas of large fires.
  2. In relatively light fuels, such as grass, herbs, and light brush.
  3. When there is an unexpected shift in wind direction or wind speed.
  4. When fire responds to topographic conditions and runs uphill. Alignment of topography and wind during the burning period should always be considered a trigger point to re-evaluate strategy and tactics.

Our study of the 440 fatalities from 1990 through 2014 shows that entrapments are the fourth leading cause of deaths on wildland fires. The top four categories which account for 88 percent are, in descending order, medical issues, aircraft accidents, vehicle accidents, and entrapments. The numbers for those four are remarkably similar, ranging from 23 to 21 percent of the total. Entrapments were at 21 percent.

But as Matt Holmstrom, Superintendent of the Lewis and Clark Interagency Hotshot Crew recently wrote for an article in Wildfire Magazine, Mr. Wilson’s common denominators only address fire behavior.

Mr. Holmstrom explored eight human factors that he believes merit consideration. I’m generously paraphrasing, but here are the areas he mentioned:

  1. Number of years of experience.
  2. Time of day (especially between 2:48 p.m. and 4:42 p.m.)
  3. Poorly defined leadership or organization.
  4. Transition from Initial Attack to Extended Attack.
  5. Earlier close calls or near misses on the same fire.
  6. Personality conflicts.
  7. Using an escape route that is inadequate.
  8. Communication failures.

He goes into much detail for each item and cites numerous fires which he said were examples. It is a thought-provoking article. Check it out.

UPDATE January 29, 2016. Larry Sutton authored an article in a 2011 issue of Fire Management Today (pages 13-17) that also explored the Common Denominators of Human Behavior on Tragedy Fires. At the time Mr. Sutton was the fire operations risk management officer for the U.S. Forest Service at the National Interagency Fire Center in Boise, Idaho.

How do we reduce the number of firefighter fatalities?

House in the Eiler Fire. Photo by Bill Gabbert.
David Shepard’s house survived the Eiler Fire, 40 air miles east of Redding, California. Photo by Bill Gabbert, August 6, 2014.

Our piece about trends in wildland firefighter fatalities generated discussion of what the data meant and the fact that there was a great deal of variation from year to year. I wrote a comment below the article that grew larger than I originally expected. Here it is:


With an average of 17 fatalities over the last 25 years the annual numbers will never be smooth or without spikes. If there were more than 30,000 deaths each year, like with motor vehicles and firearms, there would be less relative variation from year to year and it would be much easier to see a trend. The wildfire environment is dynamic and volatile, but human factors may be what most influences the number of fatalities, and that is difficult to measure or predict.

We have seen some interesting discussion, on this article and others, about how to reduce the fatality rate. A large percentage of the fatalities on wildfires are caused by medical issues or accidents in vehicles and helicopters. For example in 2014 there were 10 deaths on fires, but none involved burnovers. But having said that, off the top of my head, here are a few areas that need to be emphasized in order to reduce the number of burnover fatalities:

  • Realize that firefighter safety is far more important than protecting structures or vegetation. It’s hard to step back and watch homes burn, but it’s far more painful to watch a funeral.
  • Increase the use of simulation tools such as sand tables and computers to train leaders. Try to make it as realistic as possible, but don’t keep throwing problems at the trainee until they fail. Point out mistakes, but the simulation director needs to avoid getting on a power trip. This occasionally was a problem when we used a simulator with a bank of overhead projectors and a rear-projection screen, a system that was extremely flexible.
  • Find a way to make crew resource management more effective so that crew members feel empowered. If they see something, SAY something.
  • The first things every firefighter should consider before committing to a fire suppression effort are escape routes and safety zones. After that, anchor, flank, and keep one foot in the black. Then, escapes routes and safety zones, again and again.
  • Utilize existing technology that will enable Division Supervisors, Operations Section Chiefs, and Safety Officers to know in real time, 1) where the fire is, and 2) where the firefighters are. The Holy Grail of Firefighter Safety. When you think about it, it’s crazy that we sometimes send firefighters into a dangerous environment without knowing these two very basic things. Last month Tom Harbour told me that he was very concerned that, for example, someone in Washington would be accessing the data from thousands of miles away and order that a firefighter move 20 feet to the left. That can be managed. Making the information available to supervisors on the ground can save lives.

What are your recommendations?

USFS to use new serious accident review system

(Updated on August 9, 2014 to include a link to details about the new USFS policy, and on August 11 to correct information about the distribution of the version of the report prepared for “organizational leadership”.)

The U.S. Forest Service has created a new review process for serious incidents involving a fatality or three or more hospitalizations, called the Coordinated Response Protocol (CRP). According to the agency:

The CRP is a process now being used to ensure we learn everything possible from serious incidents so we can prevent recurrence while reducing the painful effects on those closest to the incident or accident by coordinating the investigations and reviews that are required when fatalities have occurred. The CRP uses pre-trained and designated response teams. This provides a basis for coordination and communication before any team is dispatched to an incident. This new process minimizes traumatic impacts on witnesses, coworkers and others close to the tragedy while improving our ability to gather information and learn. The CRP replaces the Serious Accident Investigation with a new process called the Learning Review. The Learning Review is designed to create learning products for multiple audiences.

A new Interagency Serious Accident Investigation Guide was used for the first report on the Yarnell Hill Fire on which 19 members of the Granite Mountain Hotshots were killed. The process prohibited causes, conclusions, and observations from being included in the public report; they were reserved for a second version of the report that would be for internal agency use only.

That process was a total failure and set a new low bar for learning opportunities following serious accidents. The USFS prohibited their employees that had specific knowledge about the fire from being interviewed.

The new protocol just introduced by the USFS also specifies that two reports be produced; one for the public and another for organizational leadership.

Ivan Pupulidy called us to say that he was the author of the new protocol. Presently he is the Acting Program Manager for Human Factors Risk Management Research Development and Application for the USFS’ Rocky Mountain Research Station. In September he will be the Director of the USFS’ new Office of Learning. Mr. Pupulidy said the agency no longer subscribes to the one-year old Interagency guide and explained that under the new system both versions of the reports will be published on the Wildland Fire Lessons Learned Center website. When asked if the causes, conclusions, and observations would be included in the reports, he said they “will not include traditional nonsense”.

Mr. Pupulidy said the information will be broken up into two reports, rather than just having one, because a single document became “lengthy and troublesome”.

Our view:

Some firefighters would argue that causes, conclusions, and observations are not “nonsense”, but are some of the more important and useful features of an accident report, and that banning them reduces the opportunities for learning and preventing similar accidents. Having subject matter experts review an accident and provide information about how and why it happened can be crucial information for those in the early stages of their career.

Any effective accident review must collect all of the information, and without censoring or overtly protecting agency officials, distribute findings that can reduce the chance of a future similar accident. As we found out, anything short of that is a waste of time and money. More than 50 people worked on the Yarnell Hill report, and could not pull it off. It sounds simple, but to get a politically sensitive agency to carry it out, apparently is very, very difficult.

In addition, innocent bystanders and witnesses with information about the accident must be protected from civil lawsuits and criminal charges.


The USFS’ description of the new policy: Coordinated Response Protocol Paper

A Type 1 Incident Commander looks at the Yarnell Hill Fire

Below is an article written by Rowdy Muir, a Type 1 Incident Commander, that appeared in the Bureau of Indian Affairs’ Smoke Signals publication this month:

What We Already Know

By Rowdy Muir, Agency Administrator Representative, National Interagency Hotshot Committee

Editor’s note: This article was written several months before the investigation report was completed and released.

On the evening of June 30, 2013, the news confirming that nineteen hotshots had died on the Yarnell Hill Fire shocked not only the fire community but the whole nation. I know there were others like myself who were wondering how something so tragic could happen to nineteen hotshots.

Rowdy Muir
Rowdy Muir, a member of the Fire and Aviation Safety Team during the Beaver Creek fire near Sun Valley, Idaho, 2013.

In 1994, after the South Canyon fire fatalities, people were asking the same question. Many were convinced that the investigation report would tell a story of some unrealistic, freakish event that claimed the lives of fourteen wildland firefighters. Yet nothing came out in the report that was unusual, phenomenal or bizarre. It wasn’t an act of God. Instead, the reality is that as a culture we read about things we were familiar with—things we should have already known.

I anticipate the same realization when we find out what happened to the Granite Mountain 19 on the Yarnell Hill Fire once the investigative report is published. My bet is thereport won’t tell us anything new hashappened. We will once again find outsomething we already know.

Make no mistake, the investigation report is valid and essential to a learning culture—perhaps even more so if it is predictable. The content will likely focus on LCES, human factors, situational awareness, values, crew cohesion, bowls, chutes, chimneys, down drafts, column collapse, point protection, tactics, strategies, independent action, WUI, structure protection and downhill egress. All topics we’ve heard before and have had many discussions about. Yet for a small amount of time, topics that were not remembered.

Gordon Graham says this “there are no new ways to get into trouble.” This rings true for the wildland fire culture.

I don’t think there will be anything that will happen which is so new or different from what has happened in the past. Somewhere down the line, we’ll see that we’ve made the same mistakes as before.

I appreciate the honest openness of Darrell Willis (Cofounder Granite Mountain Hotshots) in his interview with the news media. What he shares gives me a lot of personal mental anguish. No one has all the answers to all the questions. But the following are some things we already know:


In the news conference with crew cofounder Darrell Willis he mentions that “one of the most emphasized things we do is to establish LCES.” Yet, in the same sentence he mentions that “there are points during the day that we didn’t have [LCES] in place.”

How many times have we heard that said? If we don’t have LCES in place then there is something wrong. Even if it’s only for a moment—one might bring to the attention of others the need to establish LCES. LCES needs to be continually monitored throughout the shift. If they are not in place, then we don’t engage until they are in place.

Tactics and Strategy

In the same interview, Darrell talks about the crew abandoning a tactic of anchor and flank to address some independent action (to do point protection on the structures). Most agree that independent action is critical to the success of catching many wildfires. What we need to learn from this is that when we change tactics and strategies that are working, we need to evaluate the risk vs. gain. We need to think things out before we engage in another tactic. Someone might ask, “Why are we leaving something that’s working to take the risk of something that may not work?”

Downhill through Bowls, Chutes, and Chimneys

Eric Hipke, the only survivor from the uphill run that proved fatal for others at South Canyon, may tell you that the there is only a 1 in 14 chance of out-running a fire burning up hill. Anytime we commit to any type of downhill egress, the option of successfully going back up the hill in an emergency is “slim to none.”

This is partly because it is so difficult to measure how long it takes to get back up, and then over or through these geographical barriers. We should reevaluate any type of downhill operation, knowing that the only way to safety is back up the hill.

The Value of Situational Awareness

In an interview with Juliann Ashcraft, she mentions the text she received from Andrew about how “things are getting wild,” and how “Yarnell was looking to burn.” She acknowledges that those words weren’t common language for Andrew. It was a different scenario which she hadn’t heard from him before. Her situational awareness told her that something was different.

Why is it that Andrew didn’t recognize the same awareness? Many of us recognize changes in our surroundings, and have “situational awareness.” However, even though we are aware of our surroundings, we sometimes fail to take intelligent action based on what we observe. We get caught up in the moment and sometimes our field of focus narrows, and we don’t rely on someone else to help us with our blind spots.

We need to recognize that when the slightest thing changes we need to adjust. When I first learned to ride bulls, I was taught that when a bull makes a move you need to make a counter move equal to the bull’s move. If you made a move that was too extreme or not equal to the bull’s move, it was much harder to react to the next move the bull made. In most cases, if you can’t make counter moves equal to the bull, the consequences are you got thrown off. It takes many years of practice to be able to compensate for either over-aggression or the lack of equal aggression.

I find this to be true with situational awareness. We need to be able to recognize the change and make decisions to equalize the change. Sometimes we either overreact to the change or ignore it; the consequences are the same. We become out of balance.

Weather and the Collapse of Columns

In discussions with personnel who were on the Dude Fire, I found out that no one really recognized the collapsing column that brought about what they thought was a weather event with rain, hail and strong down drafts.

I am currently the District Ranger on a district that had three fatalities related to a similar weather event. I was on an incident in Utah a few years ago in which a homeowner had me come look at his residence which had burned down. He wanted to know why.

He couldn’t understand why the front of the yard where he had parked a truck and tractor was still green and the vehicles untouched. The front of the residence would have been the head of the fire being pushed down valley from down drafts. One would have thought all his property would have been lost. In reality the weather event caused spotting way ahead and down valley of the main fire and when finished, the fire consumed the residence from the back side because the fire took a normal route of burning uphill.

The Yarnell Hill fire had experienced some of the same types of weather events throughout the day. Those events were broadcast by radio to those on the fireline.

Whether what happened was caused by a column collapsing, a frontal passage, or the buildup of clouds which resulted in down drafts, fires that experience these types of weather occurrences should make us mindful that there is really no main or head of the fire. An established fire can, and will come from all directions once down drafts occur.

WUI and the Values at Risk

The days of “anchor, flank and pinch” were the days of firefighters being out in the woods chasing fire that didn’t have much in the way of “values at risk.” The only “values” we were asked to watch out for were ourselves. It’s rare anymore to have a fire that doesn’t include many different “values at risk” that need protecting. The perception of these “values” takes away from the real mission, and that is again, to protect ourselves as we are the real and primary “value at risk.”

Our training curriculum is fairly narrow and focuses on the mission of wildland fire. Keep this in mind: you are truly the only “value at risk.” We are truly the only value that needs to be protected. And yes, I would say the protection of others falls into the category of “we.”

No one would ever downplay the value of other lives at risk. Somewhere in our culture, our perception changed and we took upon ourselves the responsibility of structure protection. This has never been our mission or our responsibility.

I believe when we get into a WUI situation, we really need to evaluate our thought process. This situation gets our adrenaline pumping, and blurs our ability to make sound and rational decisions. Especially if we are familiar with the community or know who lives in the houses. It’s much harder for us to disengage when we have an emotional attachment to the structures in addition to the people who inhabit them.

I know all too well the emotional aspect. When I was in Florida in 1998, working in and around various communities, I grew to know and like the people in those communities. As time moved on, the aspiration of trying to save every home in every community became a personal challenge and obligation. On one occasion, we were being run over by fire and doing the best we could to save structures. During the heat of the battle, I recognized my shortcoming and pulled everyone out of the situation. The need to reassess the situation is obvious now—yet for that small momen,t I was caught up in an unrealistic task. Pulling back was the best move I ever made. The perception is real. Don’t think for a moment you can’t get caught up in it.

Values and Crew Cohesion

All decisions are based on values. I believe we should share our personal values with our co-workers and team members. The more we share our values, the more cohesive we become. If we know and understand the values of our team members, we can appreciate and accept their decisions more easily. I find this to be critical in our quest to become better team players.

Teams, as a group, also have shared values. We make decisions based on what our team’s values are. If we accept the team values, then the team reaps the rewards or pays the consequences as a team. If we only navigate by our own values, then the rewards or consequences are only ours.

There are a lot of rewards from being on a team that succeeds or excels. We see this in the film story of the 1980 US Olympic Hockey team winning gold or Shackleton’s crew navigating their way home through the Antarctic. We see it in our modules, crews, sections, and staffs.

Each individual had to give up some personal values for the team to be successful; some personal and team values don’t mix. The reality is when decisions are made as a team—when there is a consensus that “this is what we are going to do, or not do”—a team owns the decision; and the team may lose. Our value system can compromise our situational awareness.

There are no new ways to get into trouble. Our culture has been here before and I’m quite certain we will be here again—an acknowledgment that may or may not help us heal depending on how we choose to process the information—the “what we know.”

If we take what we already know and put it to good use, it will help us come to the full understanding of the real, tangible, human values at risk.