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 https://m.wfas.net) that can be displayed spatially for each of the fire danger indices separately or combined into a Severe Fire Danger Index.

[…]

Conclusions

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.

Orange County introduces pilot program for real time wildfire mapping

It is another step toward the Holy Grail of Wildland Firefighter Safety

FIRIS fire wildfire mapping real time
An example of the technician’s screen when using the FIRIS system. Screenshot from the video below.

This month the Orange County Fire Authority began a 150-day pilot program that could lead to real time fire mapping being available to firefighters on the ground. Not knowing exactly where a fire is has been a factor in more than two dozen firefighter fatalities in recent decades. Smoke, terrain, and darkness can obstruct the view of fire crews and supervisors which can severely compromise their situational awareness.

The 150-day Fire Integrated Real-Time Intelligence System (FIRIS) pilot program got off the ground September 1 thanks to funding secured in the 2019-2020 California state budget by Assemblywoman Cottie Petrie-Norris (D-Laguna Beach).

“The State of California must shift strategies to address the constant crisis of wildfires – this is no longer a seasonal threat,” stated Assemblywoman Petrie-Norris. “I am proud to have partnered with the Orange County Fire Authority in securing $4.5 million in state funds for technology that will protect lives and property by giving first responders better, stronger tools to use against the threat of wildfires.”

The system utilizes a fixed-wing aircraft equipped with infrared and radar sensors that can see through smoke. The plane provides real-time fire perimeter mapping and live high definition video to support supercomputer-based wildfire predictive spread modeling.

FIRIS fire wildfire mapping real time
Screenshot of aircraft featured in the FIRIS B-Roll video.

A supercomputer at the University of California San Diego will run fire spread projections based on fire perimeter data collected by the aircraft. The output will estimate where the fire will be in the next six hours. The fire spread model will adjust for successful fire suppression actions by firefighters on the ground and in the air. This intel allows for more timely and accurate decision making for resource allocation and evacuations.

“The ability to place resources exactly where they need to be to successfully battle a wildfire can mean the difference between lives and property saved or lost”, said Orange County Fire Authority Fire Chief Brian Fennessy. “Technology is becoming increasingly important as we work to suppress wildfires quickly. We’re hopeful this pilot program may someday become a routine asset statewide.”

For decision-makers on the ground, a common operating picture increases situational awareness. Firefighters on the front line, incident commanders, law enforcement, and regional and state emergency operation centers all could have the ability to see the same fire intel on a smartphone, tablet or computer in real-time. Fire perimeter maps and live video feeds are provided through an electronic network to assist decision-makers.

This is another step toward the Holy Grail of Wildland Firefighter Safety which would ultimately provide to fire supervisors the real time location of a fire and the location of firefighting personnel and equipment.

The video below is “B-Roll”, that is, unedited footage. The first 6.5 minutes are simply images of aircraft, but after that you will be able to look over the shoulder of the imagery technician as he observes infrared imagery of a fire, manually interprets the heat signatures, then traces the fire perimeter on the screen. That perimeter could then be electronically sent to the super computer in San Diego County which would run a fire spread model to predict what the fire will do in the next six hours.

Research: selecting the optimum escape route at a wildland fire

Escape Route Index: A Spatially-Explicit Measure of Wildland Firefighter Egress Capacity

Escape Route Index

Above: a figure from the research

Previously we covered research that is underway to help wildland firefighters determine the best escape routes from a dangerous fire. A paper published in 2017 looked at the use of LiDAR to analyze the effects of slope, vegetation density, and ground surface roughness on travel rates for wildland firefighters’ escape routes. And earlier this year we reported on research that studied crowd-sourced fitness data to estimate rates of foot travel on slopes and how it could be integrated into recommendations for escape routes.

Below are excerpts from a research paper that was published July 8, 2019, written by Michael J. Campbell, Wesley G. Page, Philip E. Dennison, and Bret W. Butler. It is titled, Escape Route Index: A Spatially-Explicit Measure of Wildland Firefighter Egress Capacity. Link to the entire document.

From the Abstract

A previously published, crowd-sourced relationship between slope and travel rate was used to account for terrain, while vegetation was accounted for by using land cover to adjust travel rates based on factors from the Wildland Fire Decision Support System (WFDSS). Land cover was found to have a stronger impact on ERI values than slope. We also modeled Escape Route Index (ERI) values for several recent wildland firefighter entrapments to assess the degree to which landscape conditions may have contributed to these events, finding that ERI values were generally low from the crews’ evacuation starting points.

From the Conclusions

In this paper, we have introduced a new metric for assessing and mapping egress capacity, or the degree to which one can evacuate from a given location, on a broad, spatial scale based on existing landscape conditions. ERI is not a single metric, but a suite of four spatially-explicit metrics that define the relative travel impedance caused by terrain and land cover faced by a fire crew, should that fire crew need to evacuate. The intent is that this modeling technique will be employed to aid in wildland firefighter safety operations prior to engaging a fire, acting as a decision support tool. Given that the metric relies on US nationwide, publicly-available datasets, the goal is that ERI metrics would be mapped in advance of fire suppression and used to direct fire crews toward potential control locations with higher capacity for evacuation, thus reducing the potential for injurious or even fatal entrapments.

ERI does not map escape routes, per se, it highlights areas that have a greater or lesser capacity for providing efficient escape routes. Areas with high ERI values will likely have an abundance of open, easily-traversable terrain, through which many potential escape routes may exist requiring little alteration of the land cover. Conversely, areas with low ERI values possess some combination of rugged terrain and dense vegetation, thus making the designation of suitable escape routes difficult or even impossible.

This is why you don’t want to be under a retardant drop

If that video does not convince you — last year a firefighter from Utah who was working on a fire in California was killed when a retardant drop uprooted an 87-foot tall tree that fell on him.

Panel details improvements on the horizon for wildland fire situational awareness

New tools being developed that can help fight fires more safely and efficiently

fire situational awareness speakers
Left to right: Kate Dargan, co-founder and chief strategist of the firefighting-analytics firm Intterra Group; James Reilly, Director of U.S. Geological Survey; and Jeff Johnson, CEO of the Western Fire Chiefs Association. Screenshot from USGIF video below.

A very interesting panel discussion titled “The Power of Real-Time Data for Firefighting” occurred at a conference organized by the United States Geospatial Intelligence Foundation (USGIF) — a nonprofit, educational organization supporting the geospatial intelligence tradecraft.

The three primary speakers during the panel were Kate Dargan, co-founder and chief strategist of the firefighting-analytics firm Intterra Group; James Reilly, Director of U.S. Geological Survey; and Jeff Johnson, CEO of the Western Fire Chiefs Association.

They discussed some tools that are slowly beginning to appear in the hands of wildland firefighters and what is being worked on that could show up in the field soon that will enhance their situational awareness. They talked about real time fire perimeters that could be displayed on mobile devices, tracking firefighting resources, and high-resolution LIDAR mapping of the entire United States — right along the lines of what we have called the Holy Grail of Wildland Firefighting.

The video below begins with introductions of the speakers and is followed by a description of the Camp Fire that burned through Paradise, California. If you’re already familiar with that incident, you  can skip ahead to 8:00 where Kate Dargan begins her excellent presentation. She became a firefighter at the age of 18 and worked her way up to the post of California State Fire Marshall and later co-founded the Intterra Group.

Here is a sample from her remarks where she described her vision of real time fire intelligence:

We need a persistent fire perimeter. I need to know where the fire is at all times. I need to know where I am against that fire perimeter. I need to know where my forces next to me are. I need to know that at a minimum of one square meter resolution. And I need to know that what is collected and served to me on my mobile device is no more than two minutes old. I need to see that in a shape file so I can put other data with it. That’s what real time means to me…That’s the bulls eye we should be aiming at.

Below is a screengrab image from the video.

Kate Dargan situational awareness wildfire
One of the slides from the presentation by Kate Dargan, co-founder and chief strategist of the firefighting-analytics firm Intterra Group. Screenshot from the video below.

NWCG approves new fire shirt design with retroreflective striping

Considered but discarded the option of high-visibility fabric for entire shirt

new wildland firefighter shirt design striping
Retroreflective striping has been added to the 2011 FS spec shirt design. Depending on stocking levels, this new revision of shirts will arrive in orders within a year or two.

The National Wildfire Coordinating Group has approved a modification to the wildland firefighter shirt to add retroreflective striping on the arms and pocket flaps. In the article below written by Tony Petrilli, the U.S. Forest Service’s National Technology and Development (T&D) Program Project Leader for firefighter clothing, he explains that it will become available through the regular fire equipment system in one to two years. He also describes how they decided on the striping, rather than high visibility cloth for the entire shirt.

The article was published June 12, 2019 at the Wildland Fire Lessons Learned Center website.


High Visibility — More to the Story . . .
JUNE 12, 2019 / WILDFIRELESSONS
By Tony Petrilli

As the U.S. Forest Service’s National Technology and Development Program (T&D) Project Leader for firefighter clothing, I would like to address some of the history and decision-making criteria concerning Forest Service “spec” garments.

A recent Blog Post on this LLC site written by Charlie Palmer [https://wildfirelessons.wordpress.com/2019/04/16/high-vis/] referred to a proposal that he sent to us at the National Technology and Development Program four years ago requesting us to evaluate high visibility (HV) flame resistant (FR) garments. While this project proposal was rejected, most importantly, the concept was not. (Another Key Point: Project proposals to T&D are vetted through an interagency fire steering committee, not necessarily T&D itself.)

Many years ago, I asked FR fabric manufacturers here in the United States about HV. A couple years after that, one of the manufacturers had developed a new HV fabric.

Current Shirt

During the T&D firefighter shirt redesign project that resulted in the current (M2011) FS spec design, high visibility yellow color fabric was one of the many fabrics considered and was wear tested by firefighters in the field. Some resultant facts and findings:

  1. Flame resistant meta-aramid (Nomex IIIA) fabric does not bond well with high visibility colored dyes to American Society for Testing and Materials (ASTM) visibility standards.
  2. Flame resistant fabric made with modacrylic fibers can be dyed with HV colors.
  3. In order to meet the minimum radiant protective performance (RPP) requirements, modacrylic fabric needs to be heavier and thicker than current meta-aramid (Nomex IIIA) fabric.
  4. Wear test shirts made from HV modacrylic blend fabric received low ratings from firefighters in terms of heat stress and comfort due to lower air permeability and heavier weight of the fabric.
  5. Wear testers found that the high visibility dyes washed out with relatively few washings and leftover fire grime in the fabric left it rather dull and faded.

It seems most everything is a tradeoff in firefighter clothing. Balances therefore need to be scrutinized and discussed. Example: Garment/fabric radiant heat protection (from the fire) is very much inversely proportional to heat loss that is human generated. HV also comes with a tradeoff cost.

Decision

Firefighters run the risk of heat stress many days during a fire season. It was therefore decided that it was not worth increasing that risk (as slight as that may be) by wearing heavier/less breathable high visibility clothing. The traits of the normal yellow meta-aramid blend shirt was determined as the appropriate balance of all fabric qualities.

Any New Developments? Retroreflective Striping

Just last month, the NWCG Equipment Technology Committee agreed to a slight modification to the 2011 FS spec shirt design. The NWCG Risk Management Committee has also been briefed on this new revision. The shirt style has been wear-tested with firefighters in the field.

The biggest change is the addition of segmented *retroreflective striping. It is limited to placement on the pocket flaps and the bottom edge of the elbow patches due to the small possibility of stored energy burns and the lack of air permeability. Placing a limited amount of segmented striping will decrease the possibility of unintended outcomes yet is a practical step toward being more visible.

Depending on stocking levels, the new revision of shirts will arrive in orders within a year or two.

In a few years, when the Product Review Life Cycle brings back the shirt project, high visibility fabric and other new technology with potential benefits will once again be considered. This year we are starting a project review for firefighter pants. Be looking for a product questionnaire coming out soon!

Any agency or department can perform their own Risk Assessment and Trade-Off Analysis. If the need for excellent high visibility qualities (instead of the very good qualities of a clean yellow shirt) outweigh the need for excellent heat loss and air permeability, investigate private vendors that sell HV garments. For buyer protection, make sure the garment label confirms certification to NFPA 1977.

Until New Shirts with Reflective Striping Arrive, What Can We Do to Optimize Firefighter Visibility with the Current Clothing?

  1. Many firefighters carry signal mirrors that coincidentally don’t work well in smoky and cloudy conditions or in the dark. Consider replacing or supplementing that signal mirror with a small (size of a marker) strobe flashlight. Some folks have reported that these flashlights are very effective. (See this “New Signaling Tools” RLS.)
  2. Trade in dirty clothing at incident Supply Units or come to a fire with a couple clean sets in your red bag.
  3. Follow The Red Book Chapter 7 direction for permanently stained or old, faded shirts—replace them.
  4. Leave reflective striping intact on helmets and fireline packs.

Besides Visibility is Dirty PPE an Issue?

Besides the lack of visibility qualities, soiled garments have been shown to offer less radiant heat protection, be flammable (if gas and oil soiled), less breathable, and may contain toxins that are harmful to the wearer. Anecdotally, I have noticed less and less super-dirty firefighters while on assignments lately. Even so, firefighters need to be educated on this issue and supervisors need to take measures to ensure relatively clean garments are worn.

Currently, T&D is working with the National Institute for Occupational Safety and Health (NIOSH) to test real-world soiled firefighter clothing for such potential hazards, then determine the risk as well as the appropriate cleaning practices.

two firefighters dirty shirt clean
A couple years ago… A Division Supervisor (me) on right in a clean yellow shirt next to a (former dirt-bag) hotshot (my son). As you can see, the soiled shirt has much less visibility quality than a clean one.

Many firefighters don’t want to be visible. They feel clean clothes and reflective striping somehow makes them look uncool. They subscribe to LCES—“Look Cool Every Second”. (Sorry, Paul G.) If someone gives you grief for wearing a clean or new looking shirt, tell them you wore out your old one. By the way, my son did not give me grief for being clean, he knows better than that. He did, however, say that I look good!

Comments or questions? Feel free to contact me at anthony.petrilli@usda.gov or 406-329-3965.


*Note from Bill: According to Reflectivetapeinfo, “The word “retro” is the key to understanding the difference between a reflective surface like a mirror, and a retro reflective surface like a bike or automobile reflector. Retro means to go back or backward. In the reflective tape industry it means to return light back where it came from and no where else.”