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Cold Cases: Unique Challenges of Investigating Fires in Extreme Cold
August 10, 2022
Canadian winters can reach sub-freezing conditions, depending on the region. In northern regions, extreme cold poses a significant obstacle for field adjusters and fire investigators. Temperatures can drop to -50°C with a windchill, and frostbite can occur in less than 10 minutes. In northern regions, extreme cold poses a significant obstacle for field adjusters and fire investigators.
Working in extremely cold conditions adds challenges to the field adjuster and fire investigator. Everything at the scene is affected, including the basic equipment. Clothing, transportation, and logistics need to be carefully considered.
The state of the scene
The condition of the scene depends on the structure itself, the nature of the fire, and the fire suppression tactics used to suppress the fire.
Figure 1: A building destroyed by a fire and encased in ice during suppression.
At -40°C, everything can be encased in ice with a thickness of anywhere between 5 cm to 8 cm. In some areas, the thickness can reach 30 cm, making it difficult to access the structure. This presents several safety hazards. Walking up to the building can cause a slip-and-fall risk, structural collapse, and falling ice.
Ice can reinforce a building that is about to collapse. In other cases, the excessive ice weight could undermine the integrity of the overall structure and result in a collapse. Hence, adjusters, forensic engineers, fire investigators, and contractors attending a site need to carefully assess the integrity of the building before entering to ensure that it is not hazardous.
All parties actively involved in these fire investigations must perform a 360-degree survey to check for the following:
- Downed electrical lines or poles
- Ice hanging from the roof might fall on you when entering and exiting the building.
- Excessive ice weight on floors and walls.
Safety hazards
Footing inside and outside of the building could be dangerous when you’re approaching. Frozen stairs are particularly hazardous, especially if ice is obscured by fire debris and not readily visible to an adjuster or fire investigator entering for the first time.
The ground might appear solid in basements where water from fire suppression typically collects. However, one wrong step can send you into freezing water up to 6 ft deep.
Figure 2: Firefighters trying to thaw a fire hose using a propane torch.
The challenges that firefighters face in cold weather may affect the physical damage to the building. Delayed or ineffective suppression due to inclement conditions, failed pump burst apparatus, buried hydrants, or frozen hoses might result in more extensive and widespread damage. These incidents tend to become larger losses due to the cold weather challenges of fire suppression.
Activities like thawing a fire hose cause a delay in fire suppression and may impact the size of a loss you are adjusting.
Examining and collecting evidence
You can make preliminary determinations at a scene. The evidence must be extracted carefully and taken to the lab or staging area when everything is covered in ice. Fire investigators are taking a large amount of evidence from the scene for examination. However, most evidence is discarded as immaterial to the fire cause.
Challenges of evidence collection
It is extremely difficult to confirm or eliminate electrical wiring as a potential cause when it is encased in ice. For example, evidence of electrical arcing damage or melting cannot be visually identified unless the ice on the wiring is thawed. Additionally, the ice typically makes wiring very brittle under cold conditions.
As with any investigation, evidence may need to be removed from the site and placed in evidence bags. Unfortunately, these bags become brittle and break easily. Even using a zip tie to close the evidence bag is sometimes challenging because these plastic materials break or snap during use.
Heating systems
Ice can prevent you from examining a room or evidence buried under frozen debris. For example, a field adjuster may not document the room’s contents when it is partially covered in ice. The ice must be melted before things can be examined or removed to avoid damaging important potential evidence. How you accomplish this depends on the scene and the resources available.
The scene’s location may dictate which equipment is available for such an examination. For example, we use two main systems to conduct the thawing process for a frozen scene. The first is the salamander heater, and the second is the Glycol Ground Heater.
Salamander heaters
Figure 3: A Salamander Heater
Salamander heaters are often used on construction sites and are great for heating spaces inside a building. These heaters have flexible ducts that allow hot air into the room of interest.
You can begin removing layers of frozen debris as the room temperature starts to warm up and the ice begins to melt. This enables the exposure of contents for the field adjuster to document or potentially important evidence for the fire investigator to consider relating to the cause of the fire. Depending on the ice thickness and the condition of the scene, the thawing process can take several days.
Figure 4: A Salamander heater in action.
The tarp in figure 4 is used to trap heat generated by the salamander heater into the space of interest. The heater is sitting outside of the building. Flexible ducts direct the hot air from the salamander heater into the room of interest. A generator is used to provide lighting and power for the salamander heater.
A real challenge under extremely cold conditions is trapping the heat in a room, especially if the ceiling space or roof structure is completely consumed. Therefore, you must insulate the area as much as possible and with whatever material you have.
It’s important to recognize that Salamander heaters present a safety concern due to the extreme heat they emit. In addition, they have been known to cause fires on job sites. Thus, they need to be watched vigilantly while in operation. This means this equipment may require a fire watch to be posted 24/7. To the adjuster, this adds costs to the claim.
Although diesel- or propane-fired, Salamander heaters also require electrical power, which might necessitate the use of a generator. This also adds a cost to the investigation.
Glycol ground heaters
A glycol ground heater is a more effective system for melting floors or localized areas. However, it is less readily available than the Salamander. The heating unit provides a reservoir of glycol that is circulated through hoses. It lays down on the floor or the area of interest, then returns to the tank for reheating.
The hoses are sometimes covered with insulation blankets or tarps that help redirect the heat into the ground or the surface being thawed, thereby speeding up the heating process. This creates an effective way to thaw important evidence in a localized area without thawing the entire room.
Figure 5: A workbench in a garage structure with hoses for thawing frozen fire debris.
The goal was to thaw this area (figure 5) to examine the fire debris and collect evidence to determine the source of ignition. Unfortunately, the ceiling space had been completely consumed. Because we only needed to thaw out the workbench, the Glycol ground heater was the more practical option. Laying the hoses on the workbench allowed them to melt the ice on the fire debris effectively.
Figure 6: A Glycol ground heater.
Glycol ground heaters have a substantial hose that can be laid down on the ground or in the area of interest. Although this heater is ideal for thawing, it is not typically available in rural areas. This means you may rely on Salamander heaters when working in these areas.
The effects of cold weather on equipment
Investigating a fire in cold weather also has a fair share of minor complications that are easy to forget or overlook. While they become a matter of course for one acclimatized to working in such conditions, they can be a constant source of frustration and setbacks for the inexperienced.
1. Battery-operated devices
Cold temperatures reduce battery capacity. As such, field adjusters must consider how long batteries might last under cold conditions. Devices and equipment may be impacted, including cameras, flashlights, voice recorders, laser measuring tools, tablets, and cell phones. Remember that your batteries may only last for a short time in extreme cold.
Battery-operated devices should be kept as warm as possible to ensure high efficiency, saving you time and money. As temperatures drop, internal resistance in batteries increases and their capacity is reduced. To mitigate this, you can buy specially rated cold weather AA or AAA batteries. Although these will add an extra cost, they can be particularly helpful compared to cheaper batteries.
1. Cameras
Many camera manufacturers designate a minimum operating temperature of approximately 0°C. Therefore, extra batteries should be kept in a warm location. If you need extra batteries for a flashlight or camera, you can tuck them into the pant pockets underneath your coveralls to keep them warm. Also, keep a small point-and-shoot camera inside your jacket in case your primary camera stops working.
When you’re moving between cold and warm environments, you risk the formation of condensation inside your camera. If your camera fogs up, it might be a while before you can continue photographing the scene. As such, you may need to place a camera in a sealed Ziploc bag to allow it to adjust to warmer temperatures before using it again.
1. The vehicle
While not environmentally friendly, you should always consider keeping your car running in extremely cold weather. Batteries produce less electrical current when it’s cold, which can lead to difficulties when starting a vehicle after it’s been in cold weather for a long time. This is a precarious situation to find yourself in, particularly if you are working alone in a remote area. Keeping your vehicle running allows for a warm shelter while trying to rest.
1. Axes or prying bars
This is especially relevant to fire investigators. The combination of thick gloves and cold weather makes it challenging to grasp tools. This introduces a safety hazard when working with an axe or pry bar in a confined space. To mitigate this, paint the handles with granular or regular paint mixed with sand at least once a year. This should be done before the onset of winter and provides an extra grip for working in the cold.
1. Writing instruments
Making notes and diagrams can be challenging at any time. Gloves make it even more difficult to manipulate small instruments. Moreover, many pens will not work in the cold, but pencils will. So, you may need to use pencils for note-taking.
Dressing for the elements
The right clothing is important for your safety and comfort at a scene, especially if you spend a lot of time at the scene. You may encounter several challenges, including fatigue and dehydration. You will always expend more energy because your body works to stay warm under cold conditions. In addition, tasks require more effort because you are outfitted in bulky clothing and heavy winter boots.
You need to eat properly to maintain both energy and body heat. Thirst is suppressed under cold weather environments. As such, you must regulate your fluid intake to prevent dehydration. You may need to take regular breaks and find a place to stay warm, possibly getting back into your car.
Always dress in layers when working in cold weather. Each layer serves a specific function protecting the wearer from moisture, cold, wind, and water. The purpose is to trap warm air and provide insulation and allow for flexibility in changing conditions. For instance, you may need to shed one or more layers as you start to work on a scene.
1. The base layer
The base layer should be closefitting, breathable, and quick-drying material. Most of that material would be polypropylene, nylon, rayon, or merino wool. Cotton is not the greatest material because it absorbs and retains water.
1. The insulation layer
While a wool sweater may get the job done, materials such as fleece provide excellent insulation without adding too much weight. Although these materials are excellent insulators, they offer poor protection against the wind. A lightweight jacket – synthetic or down-insulated – might be the best option under windy conditions.
1. Outerwear
The chief purpose of the outer layer of clothing is to protect you from wind, rain, and snow. In addition, an outer layer of waterproof, breathable materials such as Gore-Tex will allow moisture to escape while repelling water.
1. Footwear
It is beyond important to keep your feet warm and dry. Warm feet enable us to work for longer periods. Although lighter boots may be suitable when walking around, they may be less effective while standing still for a long time. During an investigation, you’re often stationary for long periods. As such, you should find boots with an insulator liner and thick soles to keep you warm.
Managing your client’s expectations
The expectations of clients unfamiliar with the extreme cold may need to be managed. They need to be notified of how quickly they can adjust the claim, the scope of the loss, and the duration of an investigation. For example, a scene could take almost two to three times longer under cold conditions than in summer weather.
Things to communicate to your client include the duration of the investigation and costs associated with the investigation. Everyone works a little slower, and everything takes a lot longer. Bulky clothes and heavy boots may make it challenging to move around. Several other time-consuming activities will contribute to the overall duration of the investigation, and this reality must be communicated with the client.
Case study
Figure 7: The remains of a motel after fire suppression.
A fire incident occurred under extremely cold conditions in a Northern Manitoba motel. This commercial loss happened on January 1, 2018, and we conducted our scene examination two days later.
The fire quickly spread throughout the building, preventing firefighters from conducting an interior attack on the fire. Instead, firefighters used aerial platforms, filling the hallways with water after the roof collapsed. As temperatures at the time were about -20°C, the water in and around the hotel quickly froze.
Figure 8: Another side of the building.
Wind speeds rarely exceeded 6 km/h throughout our 2-day scene examination. However, temperatures hovered around -32°C and reached as low as -39°C at times.
Figure 9: Another photograph of the motel building, showing more ice buildup.
To conduct the initial survey of the site, we drove around in an offroad-rated 4-wheel drive truck. The parking lot outside the building was full of ice, and there was structural consumption of the roof deck. In addition, the building was completely encased in ice, making it extremely difficult to approach the structure on foot. Even attempts to walk around the parking lot took a long time, owing to the precarious nature of the slip-and-fall hazard.
Figure 10: The suspected area of origin.
A witness reportedly saw someone throwing something at the main floor window seconds before the fire started. This gave us a fairly good idea of the area of origin. However, getting access to the room was problematic because of the ice. Additionally, because this was in a rural area, the next available glycol ground heater was several hours away. Therefore, we brought in Salamander heaters to create thawing conditions.
Figure 11: The excavator brought in to peel off the exterior wall.
All the water inside the hotel had frozen, and the pressure from the expanding ice had burst open the front doors. As a result, we had to bring in some heavy equipment. We used an excavator from a local mining site to help peel the exterior wall from the suspected room of origin. We subsequently removed exterior walls from the abutting rooms to the area of origin. This allowed us to get a better idea of the room’s layout.
Figure 12: A motel room undamaged by fire (left) and the room of origin (right).
The room on the right (figure 12) had severe fire damage and was the area of interest. A substantial portion of fire debris was on the floor, all frozen solid. We needed to thaw out the debris to determine the cause of the fire.
Figure 13: A photograph of the room of origin during the thawing process.
As shown in figure 13, we used tarps to close off the room. The flexible ducts allowed the heat generated by the Salamander heater to enter the room, resulting in the thawing process. We estimate that there was approximately 3 ft of frozen debris from the collapse of the ceiling, which needed to be cleared before we could investigate further.
The Salamander heater ran for two days, during which we removed layers of debris using pry bars as the debris started to thaw out slowly.
Figure 14: Wiring and the remains of some of the furnishings within the room.
We were able to excavate the debris after the room had been thawed. The floor had various segments of wiring that were examined to rule out evidence of electrical failures. We also looked for furnishings, remains of springs from couches and beds, and equipment such as light fixtures to determine their possible involvement in the cause of the fire.
Origin and cause
The top-down patterns on the floor under the window confirmed that this was the room of origin. Based on the fire patterns, the fire spread through the ceiling of room 105, into the hallway corridor ceiling, via a construction feature that created a void space between the drywall ceiling. From the hallway ceiling, it spread throughout the entire building, even to inaccessible areas. This made it difficult for the fire department to suppress the fire.
This fire’s cause was identified as a provocative act involving an ignitable liquid. Based on eyewitness reports and our investigation, we suspect a device, such as a Molotov cocktail, was thrown through a window of this motel room, resulting in an incendiary fire.
The fire then broke out into the ceiling space and across the roof structure of the entire building, causing extensive damage and a total loss. Some of the extensive damage was partly because of the cold weather conditions at that time and the difficulty faced by the fire department in suppressing the fire.
Conclusion
In many ways, fire investigations in cold weather are no different than in warm weather. A client asks you to investigate the origin and cause a fire. You travel to the scene, examine the building, take photos and notes, conduct interviews, document and remove evidence for a closer inspection, and finally arrive at a conclusion after analyzing all the information.
Regardless of the temperature, the same steps must be undertaken, followed by the same procedure. In that respect, the cold makes no difference. However, the cold makes everything more difficult, complicated, time-consuming, and costly, leading to frustration and poor decision-making. More than ever, proper planning is essential for a successful scene examination and fire investigation under extreme cold weather conditions.