Where Did That Fire Start?

A new research study begun by Albert Simeoni, a researcher at Worcester Polytechnic Institute (WPI), will help fire investigators better understand how wildfires start and aid firefighters in preventing, managing, and stopping wildfires. However, Simeoni says his research also will advance forensics capabilities for all investigators as it validates existing forensic tools.

“Fire is fire,” he says. “There are many commonalities, especially on the scientific side. Highlighting the need and quantifying the relationship between fire dynamics and fire scars will bring more knowledge to the fire forensics community, even if it’s not the same context. Knowing the speed that fire spreads and how fire intensity creates scars helps everyone.”

However, Simeoni stresses there also are forensic challenges that are unique to wildfires. A building is not alive, but vegetation is. The weather outside also plays a role. And it’s hard to pinpoint the fuel element, especially with scrub land. 

“We come in and it’s destroyed,” he says. “It’s a little different from an industrial plant, but it can be a factor in those fires too. For instance, with transit storage, you may not know what you had when the fire started. With wildfires you only have a general picture of what it was, and you need to do a lot of reconstruction.” 

He adds, “It’s also a spreading phenomenon. It changes in intensity all the time.”

Likewise, a fire in an industrial plant is limited to the facility itself and perhaps neighboring buildings. In contrast, wildfires have no boundaries. “This makes saying ‘that’s the way it happened’ challenging. If it’s very windy, you’ll have multiple ignitions,” he says.

Let’s say there is a power line nearby. An investigator might conclude the power line ignited the vegetation below. But maybe a worker in the area did something to ignite the fire. 

“When you have multiple ignitions, the problem comes in attributing the loss to one of them,” he says. “It’s very difficult to do.”  

Understanding these challenges, Simeoni and Nicholas Skowronski, a research forester with the U.S. Forest Service, aim to research wildfires and develop baselines that help investigators better pinpoint origin.

PINPOINTING ORIGIN

Simeoni began researching wildland fires and modeling spread as he pursued his Ph.D. in France. Since then, he’s sought to better disseminate his research in the fire world. With that goal in mind, the professor and head of WPI’s Department of Fire Protection Engineering applied for a grant with the National Institute of Justice (NIJ) to further his research and disseminate it to more individuals. 

Recently, Simeoni received a $519,893 NIJ grant to evaluate the reliability of burn pattern indicators used by investigators to determine the origin of wildfires. He plans to use a laboratory wind tunnel, field studies in a New Jersey forest, and data analysis to determine if scars on a landscape, ash deposits, and other indicators used by investigators reliably point to where a fire originated. 

“When we base investigations on burn pattern indicators that are not scientifically verified, those investigations have consequences for the people impacted by the fire, for government agencies, and for companies,” he says. 

Validating the tools used to evaluate origin comprises much of the research. Simeoni explains most investigators see the methodologies used for fire investigation as good, but little research quantifies the reliability of the methods they use.  

“We want to be sure we provide investigations the best tools available,” he says. “We’re not reinventing tools with this study, but we’re looking at the reliability of the tools investigators already use.” 

The study also zeros in on the reliability of fire indicators and fire scars when explaining how fires started or who is responsible. Investigators examine the shape of burnt grass, the angle of char left behind, craters formed in rocks, marks on buildings, and other physical signs of damage to trace a fire across the landscape to its origin.  

“I recognize there is a need for further research, so I geared my study toward addressing a need,” he says. “Investigators do not look at one indicator to tell the story, they look at the whole picture. That’s why it’s called fire pattern. This picture requires investigators to thoroughly understand fire, fire behavior, and fire dynamics to understand fire scars.” 

Simeoni explains as an example, the 2016 version of the National Wildfire Coordinating Group guide for fire investigation names 14 fire indicators and drops three as unreliable. “We want to see if it was right to drop those indicators and determine other ones cause the problems,” he says. “If you’re looking at fire patterns, you may not have all 14 indicators at the same time. Then you have to make your determination based on your best judgement for the indicators you can collect.”

FIRE FORENSICS TECHNOLOGY IMPLICATIONS

Simeoni will use a wind tunnel, a sloping bench, and live burns to zero in on indicator reliability. The technology will help him emulate diverse fire conditions to see how they influence indicators. 

A wind sloping bench looks at the impacts of wind on fire spread. For instance, what happens if fire spreads with the wind, against the wind, or on a downward slope? He also will use a 20-foot wind tunnel and burn pine needles, grasses, and other vegetation under varying conditions such as wind speed, fire intensity, and moisture. 

“We will simulate different winds and different slopes with our wind tunnels,” he says. “We will use a sloping bench and will simulate different fire intensities, vegetations, and supports. The research will help us learn if indicators are problematic in some conditions. When you focus on those, they might give you a false reading. Or we may say this one is iron clad; no matter what happens, this indicator will be clear.”  

Simeoni also will work with local fire service partners to measure locations before and after a controlled fire. They will use a handheld laser to scan vegetation before and after the fire. “Getting a 3D presentation is pretty new,” he says. “It’s like the movie ‘The Matrix.’ You can turn it and move it and see exactly what happens.” 

It also will show how elements at the scene might impact fire spread. In one case, Simeoni says fire spread through a fence, but when looking at indicators, investigators initially thought the fire spread in another direction. “We realized, using our cameras and our analysis, that there was a spot fire,” he says. “The fire was spreading in one direction and the spot fire showed it going in another.” 

FIELD TESTS AND ANALYSIS

Simeoni will study fire indicators in the field in collaboration with firefighters from the New Jersey Forest Fire Service, who manage controlled fires in the New Jersey pine barrens. He will augment lab findings with research from the field. He will then compare results from field and lab studies to get the results of investigations conducted into fires that burned under similar conditions. 

“Lab experiments will see how findings correlate with parameters,” he says. “Going into the field with investigators after a controlled burn will also help. Investigators will do a blind investigation. We will know how the fire spread because we measured everything, but investigators will know nothing. This will help us identify any gaps in the indicators.” 

The result of his three-year study will be research Simeoni plans to share with public and private fire departments. The project, he says, could validate existing forensic tools and help fire investigators work more efficiently with fewer errors. 

“Understanding where a wildfire starts can help determine how it started, and who, if anyone, may be criminally or financially liable for damages,” Simeoni says. “As a researcher and scientist, I know that understanding how fires start can help us determine how to prevent, manage and stop them.”