Close Calls: Smoke Explosion at a Strip Shopping Center

July 19, 2021
Billy Goldfeder is impressed with the awareness of members of the Lenoir, NC, Fire Department to back off from the front of a strip mall store moments before a smoke explosion.

On Feb. 23, 2021, the Lenoir, NC, Fire Department (LFD) responded to a fire at a commercial strip mall. The members experienced a smoke explosion early on. When I saw a video of the incident, I was intrigued, because it shows LFD firefighters approach, but then, moments before the explosion, they back away. It was their knowing to back off that caught my interest.

Capt. Greg Cannon and Firefighter Dakota Davis approached the front door then took it to gain access to the structure. Cannon said they felt the pressure—and the glass—hit them.

Fire & community overview

The city of Lenoir, NC, is located in the foothills of the Blue Ridge Mountains in western North Carolina in the county of Caldwell. The population of the city is 17,933 as of the 2020 census.

In 2021, the LFD expanded its services by providing the city with three fire stations and 58 members. The LFD provides fire protection, fire prevention & education, a fire marshal, rescue and backup EMS for the city and county. The department has specialized teams for high-angle rescue, swiftwater rescue, trench rescue, and search and rescue. The LFD annually responds to 3,000–3,200 calls per year. Because of COVID-19, the department’s response calls were about 1,900 in 2020

LFD members work a 24/48 rotation; battalion chiefs rotate on a modified 24/48.

LFD headquarters houses: Ladder 1 (a 75-foot quint) and its captain, driver operator and two firefighters; Rescue 1 (a heavy rescue) and its lieutenant, driver operator and firefighter; the reserve Engine 1; Tower 1 (a 100-foot aerial platform) and Rescue 10 (an ambulance).

Station 2 houses: Ladder 2 (a 75-foot quint) and its captain and firefighter; Engine 2 and its lieutenant and firefighter; and a mobile air unit.

Station 3 houses Engine 3 and its captain and two firefighters and the duty battalion chief.

On any structure-related incident or working fire, all stations respond. The rescue company responds to all motor vehicle accidents. The LFD receives and gives mutual aid to neighboring departments.

The day of the fire, the LFD called for mutual aid from Hudson Volunteer Fire/Rescue (HFR), Gamewell Volunteer Fire Department (GVFD) and North Catawba Fire-Rescue (NCFR) . Kings Creek Volunteer Fire Department (KCVFD), Sawmills Volunteer Fire and Rescue (SVFR) and Valmead Fire-Rescue (VFR) provided fill-in and back coverage for the city.

Our sincere thanks to the LFD personnel, including with Fire Chief Ken Hair, his chief officers, the Caldwell County 911 Communication Center personnel and all mutual aid resources, as well as Chief David Dodson and UL’s Steve Kerber, for their assistance with the article.

Account from Cannon

Ladder 2 (L2) arrived first on scene and reported smoke showing from the front of the structure, which was a commercial strip mall-type building. I advised the next incoming truck to secure a water supply and to lay it to L2. The smoke, initially observed, was gray in color and was what I would call a “lazy” type smoke. It wasn’t pushing or appearing to be under pressure. At this point, given the approximate size of the building (8,800 sq. ft.), I figured we probably had a two-room fire.

I instructed Davis to deploy a 200-foot 1¾-inch hoseline to begin an initial attack. I helped him stretch out the line and went back to L2 to retrieve the thermal imager. I returned to the front of the structure and tried to open the door, but it was locked. There was another glass door to the left, but it had security bars over it from top to bottom, so it wasn’t an option.

Davis asked me whether I wanted him to take the unbarred door, and I told him, “Yes.” As soon as he popped the glass, I observed the smoke level drop immediately, from about chest level to the floor. I also observed smoke being drawn back into the building, which I knew from years of training and teaching was a bad, bad thing. I advised Davis to “Back up, back up!”

It was at this point that the backdraft/smoke explosion occurred. I could see Davis on the ground to my right. I thought the blast knocked him down, but he advised that he fell as he was running. I could feel the glass, which blew out the front display windows, hit me in the back as we retreated.

Battalion Chief Scott Powell arrived just as the blast occurred and assumed command. After checking to see whether we were alright, he called for a defensive attack only. I then advised him via radio that I believed that the fire was in the cockloft.

Ladder 1 (L1) with Capt. Travis Morrow had arrived, after laying a 5-inch supply line to L2. Morrow came to me and asked whether I wanted him to check around the C side of the building. I advised him, “Yes.” I instructed Davis to begin flowing the 1¾-inch line into the building from the door that we took out and not to stop. Engine 3 (E3) then arrived, secured a water supply and deployed a 2½-inch hoseline to the same approximate location as L2 to assist. I stayed pretty much at this same location (A side) for the duration of the incident.

Account from Powell

As the battalion chief, I arrived approximately two minutes after L2 and observed light gray smoke coming from the front of the structure with a little around the roof line on Division B. L2 was flaking out a 1¾-inch hoseline and getting into position for an interior attack.

At that time, there was no indication of a large fire because of the smoke conditions that were present.

Cannon and Davis went to the front door and found smoke level about chest high. The front doors were locked, so Cannon had Davis take the glass door to make entry. The taking of the front door wasn’t intended for ventilation; it was to gain access to the structure because of the security of the building. At this point, I was positioning the battalion vehicle out of the way for incoming apparatus. I observed Cannon and Davis ducking and back-stepping as they observed the smoke being drawn back into the structure. Within a split second of taking out the front door glass, the backdraft/smoke explosion occurred. I saw Cannon still standing, and Davis was falling to the ground. I still was in the battalion vehicle and immediately had all units hold traffic to check on their safety. After talking with Cannon via radio, he advised that they were OK, and I transmitted a defensive fire only at this time.

As the backdraft/smoke explosion occurred, the roof on the B/C corner was compromised and self-vented.

As the incident commander (IC) once the defensive fire was transmitted, I had L1 position to the B/C corner of the structure for aerial operations as well as L2 operate as aerial operations on Division A. I had E2 lay in a secondary water source to L1 and then utilized E2 to secure what utilities they could and to force the rear door on the structure, which was about a six-foot opening, to assist in fire attack through that opening with a 2½-inch smoothbore.

E3 was assigned to deploy a 2½-inch smoothbore to Division A to assist L2 with fire attack. The backdraft/smoke explosion blew out two of the large glass windows, and L2 and E3 took out the others with pike poles. Doing this gave crews large openings for exterior fire attack.

Cannon and I had L2 position the ladder in the front openings, so the operator could flow the stick deep into the structure while E3 used the 2½-inch hoseline to protect the fire wall to the adjacent business.

All the above happened in about a 12-minute timeframe. As the IC, I saw the need for additional resources. I contacted Caldwell County 911 Communication Center via radio and had it dispatch all off-duty city of Lenoir firefighters to the scene. I requested a four-man engine company from Hudson Fire Department and Gamewell Fire Department. With this request, I also received Caldwell County Emergency Management with a crew of two. Also, I placed KCVFD, VFR and NCFRon standby.

When the additional companies arrived, I had those crews search the adjacent business to double-check to ensure that all occupants were indeed out and accounted for. The search did confirm that all were out. During the search, crews noticed that the fire wall was starting to breach to heavy fire against it. Once the search crews came out, the call for a trench cut was made, to stop the fire and to keep it from adjacent businesses that were within the building. At this time, I requested NCFR and SVFR to stand by with a four-man engine company at Lenoir Station 2 location.

Tower 1 arrived and was set up on Division A for crews that were going to the roof for the trench cut. Ground ladders were placed on Division A and Division C for a secondary means of egress. Where these crews operated, the roof integrity was in good shape. The trench cut crew also had a handline in place for their safety. The trench cut was complete and assisted in preventing fire from reaching the adjacent business. Crews were pulled back to staging and rehab and waited for further assignments.

Account from Greer

As I approached the building, I could see heavy dark smoke coming from the rear of the building. There was some smoke coming from the front, but it wasn’t pushing like it was in the rear. E3 had arrived and was pulling a 2½-inch handline to the front of the building. I met up with my crew, and we took the 2½-inch handline and started suppressing the fire at the front door.

The smoke level in the building was about a foot from reaching the floor. You couldn’t see any fire from the front, just heavy black smoke.

Another crew started to take out the front windows, and we moved the 2½-inch handline from the front door toward the fire wall that separated the store from [a neighboring business]. We moved and suppressed the fire through the windows that were being taken out. We were trying to stop the fire from spreading into the next business.

As the windows were taken out, the smoke that was inside of the store lifted enough so that you could see where the fire was burning. My crew stayed with this handline, providing a water curtain down the fire wall until the fire was contained.

Comments from Hair

First and foremost, I am thankful that no one was injured during this incident. The first on scene officer/crew reacted and performed as they were trained.

Upon arrival and based on the smoke conditions that were observed and on statements that were provided, I believed that this was going to be, at most, a two-room-and-contents fire in a commercial building. Upon my arrival, they were breaching the store front door to gain access to advance a hoseline for extinguishment. Once the officer realized forced entry was changing the scene dynamics and observed a change in the fire behavior conditions, the officer immediately started backing the crew out of the situation. It was apparent to me that the officer paid attention and was knowledgeable enough about the rapid change in conditions to avoid injury to his crew by withdrawing operations to ensure safety. I believe that this knowledge was due in part to the good work that our training division has done in educating officers and staff in “reading the smoke” (we had the opportunity to take David Dodson’s excellent program, “The Art of Reading Smoke,” and fire behavior classes).

When I arrived, I only observed Division A/B. I planned on completing the 360-degree size-up when I got out of the vehicle, but when the backdraft/smoke explosion occurred, my immediate attention went to the crew and its safety, so I didn’t complete a 360. However, L1 did complete the 360 for me, because they were positioned on the B/C corner.

Also, great leadership was bestowed by the battalion chief/incident commander to immediately ensure the safety of the crew that was affected, to remain calm and to correctly change operations strategically to a defensive attack.

Driver Rodney Woods’ placement of L2—approximately 40 feet from the building—helped tremendously. The LFD has seen FDNY use its tower ladders as master streams in front doors in a defensive attack. This helps to keep firefighters out of collapse zones.

Something that must be remembered from this incident is that breaching for entry causes ventilation effects, whether that’s your intent or not. Some departments have reached out to me about this fire to say, “Why didn’t you vent the roof and that wouldn’t have happened.” I have stated that ventilation wasn’t the intent.

The officer observed conditions where the smoke was chest high, and he could see through the business, and no fire was detected. His statement to me based on conditions was that he believed that it was a room-and-contents fire, at most, two rooms. He breached the door front to gain access to advance a hoseline for suppression. Upon the ventilation effect, it changed the conditions rapidly, and he anticipated what was about to happen and immediately started moving back.

A lesson that I would like to point out is that when you teach ventilating, you should move to the side, because the rapid release of fire gases can have the effect that occurred at this fire. (We take for granted, even in training, that you practice moving to the side when you mean to ventilate.) This is something that we will train on moving forward.

Also, we have breached numerous doors, and nothing like this ever happened. We tell stories that no two fires are the same, even in the same type of structure, but do we actually operate with this in mind? We know that fires react differently based on fuel loading, building construction and other extenuating circumstances, but do we get lulled into the notion that we simply can do what we always did and get the same successful result that we have had?

Furthermore, we must ensure that we stay up to date on our district’s pre-incident surveys/preplans. These give the officers/staff advanced knowledge of important issues, including construction factors, redesigns, layouts, fuel loadings and special concerns. These are valuable tools for commercial structure fires if they are updated appropriately, if staff is educated on them and if they are utilized. They can anticipate fire growth/spread and hazards.

In our city, some buildings change occupancy quite often, and we must be informed of these changes and pass the information along to all of the staff. Our fire prevention staff is expected to integrate information they find into our preplans.

Finally, the most important lesson learned is that every moment is a teachable moment—not just catastrophes. Leaders should use every opportunity to grow and advance their firefighters.

Comments from Chief Goldfeder

In this column, many fire departments have shared their lessons learned, particularly related to commercial fires, with the common denominator being not to use residential tactics at nonresidential fires.

Although different dwellings can create different challenges, compare your average single-family dwelling with the fire that the Lenoir firefighters dealt with. As we have discussed many times, your tactics must match the structure and conditions. A tip of the helmet to Cannon for his awareness in watching the smoke after taking the glass. Anytime an opening is made (regardless of the tactical objective), watch what the smoke does. The captain’s reaction was perfect.

Another critical factor is staffing. When you arrive at a fire you consider:

  • What do you have/conditions? (size up)
  • What do you want to accomplish? (water supply, entry, search/rescue/fire control, ventilation, etc.)
  • What are your resources to get the job started?

You can’t be successful in the above goals if you don’t have adequate staffing. Adequate staffing means your first-alarm assignment matches what’s reported. Anyone can call for more help after it’s needed. What’s critical is that your first-alarm assignment matches your initial, simultaneous tactical goals, which is fully preplannable. Fortunately, the LFD had adequate staffing for an initial first alarm, compared with many cities and jurisdictions of their size and economic makeup. They also called quickly for additional staffing.

Although many career departments constantly fight the staffing battle, and so many on-call volunteer departments continue to have grave levels of response (both in staffing and time to turnout), the solutions are challenging. It’s when a department knows that it doesn’t have the staffing that’s needed for predictable and measurable first alarms that alternative resources must be applied. In many areas, that’s automatic mutual aid/box alarms, which will increase the chances of a better turnout. Either way, it’s incumbent on fire service leadership to pay attention to the facts, the numbers and the reality of resources and to implement changes that benefit the public.

Dodson reminds us not to be fooled by “lazy smoke.” It’s more important to look at the velocity of smoke (speed/flow) in relation to the element that’s exhausting the smoke.

In this case, the lazy smoke was exhausting from structural elements (roof, façade, sealed seams), all of which keep out wind and rain. So, naturally, the smoke loses its velocity and color as it is heat-forced out of those cracks and seams.

Another reading-smoke shortcut was at play here: Any rapid change in smoke conditions means a hostile fire event is either taking place or is about to.

Kerber and his UL team have taught us (through UL testing) that once free-burning fire goes ventilation-limited within a building, any smoke that leaves the building will lose its velocity suddenly and likely will change to a neutral gray color. Some of the reading-smoke rules get masked when a fire is vent-limited.

The UL Firefighter Safety Research Institute and its group of firefighting subject matter experts took time to study strip mall fires.

So, between UL’s research, this article, and taking courses and related training, you can minimize a negative outcome.

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