Storage Unit Fires: Hazards Unknown

BY JOSEPH T. BERRY

The self-storage facilities considered below are generally one- or two-story buildings featuring prefabricated lightweight metal or concrete-block construction. Although they share similar problems and hazards with all self-storage facilities, these construction types seem to suffer the most at fire incidents.

The incident commander’s (IC’s) major concerns operating at a fire at a self-storage building are the lightweight construction’s collapse potential; the enormous amount of sometimes densely packed, combustible contents; and the unknown hazardous materials or liquids stored within.

Self-storage facilities are in almost every large city, suburb, and rural area throughout the United States. Overall, most self-storage facilities are safely and securely managed. But unfortunately, some facilities fall short. To rent a storage space, the person renting signs a renter’s agreement, which prohibits, among other things, the storage of flammable liquids, gases, or other hazardous chemicals or materials. But unless the proprietor visually inspects the storage items, renters may store prohibited items anyway. The fire codes for these facilities vary from state to state.

(1) Is this a business or a residence? Are civilians living here? In the past, civilians have used these for residences. (Photos by author unless otherwise noted.)
(1) Is this a business or a residence? Are civilians living here? In the past, civilians have used these for residences. (Photos by author unless otherwise noted.)

Self-storage offers a reasonable rent for businesses and consumers alike. Commercial users may store furniture, inventory, or supplies and equipment. Noncommercial renters may store excess household goods, seasonal recreational equipment, and vehicles. To save money and make efficient use of a storage unit, it may be packed from the floor to the ceiling and from wall to wall to avoid paying more for a larger unit.

The health and safety of firefighters operating at these stubborn, hazardous, and labor-intensive fires are the primary concerns for the fire service. You must share with others in the fire service any unforeseen problems encountered and the different hazards found in self-storage fires; such information is invaluable for the IC operating at the fire. Past fires are the “lessons learned” for the fire service.

Every fire district with a self-storage facility in its response area should know before any response its construction type, the apparatus access issues, the water supply available for operations, the facility’s interior alarm system, and the type of contents stored-especially that of commercial renters. You must create a prefire plan and conduct hands-on drills at these facilities.

Life Hazards

The health and life safety of firefighters are the fire service’s main concerns. Some civilians have used these storage units as living spaces or as workshops and offices (photo 1). In one instance in Orange County, New York, a person who was growing hallucinogenic mushrooms in a storage unit was also living inside the unit. In another incident, security personnel were found to be using a storage unit as a shelter. Table 1 shows some of the unknown hazards found at various incidents.

Self-Storage Fire Incidents

According to information released by the federal Department of Homeland Security, police investigations, foiled terror plots, and past terrorist attacks, terrorists have used storage facilities including self-storage units to store explosives or other supplies prior to attacks. Many fires, however, occur as the result of noncode-compliant storage of hazardous materials.

  • Fort Myers, Florida, March 2008. Investigation of the source of a foul odor emanating from a storage unit revealed a dead body found inside the storage unit. The death was determined to be from natural causes.
  • Pompano Beach, Florida, January 5, 2016. A man’s body was found inside a burned self-storage unit as firefighters extinguished a fire.
  • Spokane, Washington, January 17, 2008. An explosion and fire were reported to dispatch; one storage unit door had blown out, according to witnesses. This could have been from a backdraft or another cause. On arrival, fire units found a heavy smoke condition and a well-advanced fire in a 50- × 200-foot lightweight metal building; 17 storage units were involved. Among the contents, they were surprised to find cars, a boat, acetylene oxygen equipment, propane tanks, and contents packed floor to ceiling. They had no knowledge of where these hazards were located. The structure had high ceilings and doors, and accessing these units was difficult. The cause of the blast was undetermined.
  • Colorado Springs, Colorado, February 2015. At 1604 hours, dispatch received six calls reporting an explosion and fire in a self-storage building. The 40- × 250-foot lightweight prefabricated metal structure had back-to-back units. On arrival, firefighters found smoke pushing out from both ends of the building; four storage units were involved. The IC implemented a defensive operation. After knockdown, during overhaul, firefighters found gasoline cans in one unit and one-pound propane bottles in another. The cause of the explosion was undetermined.
  • Waterbury, Connecticut, February 17, 2015. On arrival on a frigid day, the fire department found heavy smoke pushing out of the eaves from both ends of a single unit in a lightweight steel storage building. The 12,000-square-foot building had 118 units, including 70 heated ones that were accessed through the structure’s interior hallway.

Ladder company firefighters began opening up a few units outside and entered the building in search of the fire. Two adjacent hallways led down the entire length of the building with storage units on both sides.

(2) The unknown hazards may include these five-gallon cans of flammable liquid to which foam was applied. [Photo courtesy of the Spokane (WA) Fire Department.]
(2) The unknown hazards may include these five-gallon cans of flammable liquid to which foam was applied. [Photo courtesy of the Spokane (WA) Fire Department.]

Firefighters forced entry to fire-involved storage units inside. The engine company knocked down the fire in each unit; a high-heat condition was present inside. As the truck company continued to open up additional storage units, the knocked-down fires in the previous units lit up again. The fire was traveling faster than companies were able to contain it because of the common open space at the ceiling.

Also, the interior attack was aborted because of the lightweight unprotected steel construction, the heavy content fire load, and the fire’s fast-moving intensity. The IC decided to let it burn because the building’s structural stability was questionable. The fire destroyed 115 units. The incident became an extended operation, and the water runoff froze and created a sheet of ice around the perimeter. Slips and falls are common causes of firefighter injuries.

Construction

In addition to the fire’s location and how and where it is extending, the IC needs to know the building’s construction type and what is stored inside. Consider that, with a heavy fire load of combustible contents and the storage building’s lightweight construction, a free-burning fire will likely compromise the building’s structural integrity. Furthermore, unknown and potentially dangerous contents inside-hazardous materials, chemicals, and flammables-create additional safety and health issues for firefighters and civilians alike. In past incidents involving an explosion prior to the fire department’s arrival, the IC must consider that the structure’s stability could already be compromised.

(3) This propane tank is another hazard found under densely packed contents. The source of the fire was undetermined. [Photo courtesy of the Spokane (WA) Fire Department.]
(3) This propane tank is another hazard found under densely packed contents. The source of the fire was undetermined. [Photo courtesy of the Spokane (WA) Fire Department.]

The Fire Department of New York uses a critical information dispatch system (CIDS). Each fire unit has an assigned administrative inspection area. Building inspections are conducted three times a week, and information such as the construction type (especially at new construction sites), the presence of any hazmats or chemicals, irregular floor layouts, and other vital details that could jeopardize the safety of firefighters or affect fire operations are entered into the CIDS. Units responding to that address in the future will receive that vital information printed on their response ticket, and it will also be transmitted over the radio network.

Roof Systems

The roof system for these lightweight buildings could be either pitched or flat, consisting of dimensional lumber, wood trusses, a long spanned steel frame, or open-web bar joist trusses. The lightweight metal buildings have corrugated metal sheets fastened to steel supports. These steel frame supports have been found to be four to six feet on center (photo 4).

When this unprotected lightweight steel framing is exposed to a free-burning fire, the metal supports will soften, sag, and eventually fail. The heat is conducted to this metal surface, which will retain the heat. One sign of fire exposure is the discoloration of the metal corrugated roof. Severe thermal burns may result from skin contact with this hot metal surface.

The roofs are designed for rain and snow but not for the weight of five or six fully equipped firefighters operating on it when a raging fire is below. A firefighter operating on this roof under a blinding smoke condition could sustain serious injuries or loss of life from falling into a burning storage unit.

(4) Cutting the roof can be extremely dangerous since the steel roof supports can be four to six feet on center. A firefighter cutting such a roof can fall into a burning storage unit. [Photo courtesy of the Spokane (WA) Fire Department.]
(4) Cutting the roof can be extremely dangerous since the steel roof supports can be four to six feet on center. A firefighter cutting such a roof can fall into a burning storage unit. [Photo courtesy of the Spokane (WA) Fire Department.]

On August 3, 1994, a firefighter lost his life while operating on the roof of a self-storage building on fire. The roof collapsed as he performed ventilation and he fell into the storage area. Although the firefighter was able to force his way into a hallway, he was trapped by interlocking doors and a heavy fire condition. Maze-like conditions hampered rescue efforts.

Once the fire is defined and knocked down, perform ventilation from an aerial or a bucket ladder to relieve the heavy buildup of smoke, and do not rest the bucket or aerial ladder on the roof’s surface.

I do not recommend operating on these metal roofs or ever on any truss type roof! That’s why it is so important to have prior knowledge of the building’s construction and type of contents.

For roof ventilation, portable ladders have been used as bridging platforms, spanning the wide unsupported opening and resting on the steel roof supports. This is a very dangerous tactic and is primarily used in an area distant from the fire. However, you must define the roof supports before implementing this tactic, and be aware that a cut section of a lightweight corrugated metal roof is razor sharp and could cut through a firefighter’s glove or bunker gear, severing a tendon or cutting an artery. Before implementing this tactic, firefighters must determine the type of roof construction, its structural stability, and the risk vs. the gain. Portable fans could provide the needed mechanical ventilation.

(5) The common opening for storage facility ventilation provides an excellent avenue for horizontal fire extension throughout the building.
(5) The common opening for storage facility ventilation provides an excellent avenue for horizontal fire extension throughout the building.

The square footage of the self-storage building with the number of individual units depends on the size of the facility compound. Access roads to the storage units can be quite narrow, so evaluate apparatus placement between the buildings on narrow access roads. Consider the potential damage to the apparatus from fire, smoke, or water runoff contaminants. Some facilities also provide outdoor rental space to store some larger items such as recreational vehicles, boats, trailers, cars, and trucks. This can possibly obstruct fire operations and apparatus accessibility.

Another type of self-storage building has back-to-back storage units with two separate access roads on either side. Lightweight metal partitions separate the three sides of the individual storage units. Some of these back-to-back buildings were found to have an adjustable rear wall partition, allowing a 10- × 15-foot storage unit to be expanded to a 10- × 25-foot unit. This will also have two separate entrances on two different access roads. Fire extension throughout these buildings will be transmitted by convection and by conduction. Usually, the top of each unit has a common opening for cross ventilation. This common opening creates an excellent avenue for horizontal fire extension throughout the building (photo 5). When the fire is in the free-burning stage, heat conducted from the hot metal partition against any adjoining storage unit will ignite combustible contents in adjoining storage units.

Smoke pushing out under pressure from numerous storage units or along the entire length of the building indicates a well-advanced fire. Recognize the potential for a backdraft and the possibility of a violent explosion from unknown hazards such as gasoline, propane, or other chemical or material reactive substances. Why risk a firefighter’s life in an offensive operation when smoke and fire conditions call for a cautious defensive attack?

(6) At this two-story, concrete-block construction self-storage building, of what type of construction is the second floor?
(6) At this two-story, concrete-block construction self-storage building, of what type of construction is the second floor?

Two-Story Structures

Two-story self-storage buildings are usually constructed with concrete block walls and flat or pitched truss roofs. The additional hazards include storage contents burning on two levels, no horizontal second-floor ventilation, and the possibility of unprotected floor and roof joists or trusses (photos 6-8). A burned-out second floor could suffer collapse from the weight of water-soaked contents or structural floor failure from fire and heat. With block wall construction, look out for cracking in concrete block and smoke pushing out and for the wall bulging laterally. The floor and roof are what keep the wall stable; without that stability, it is effectively a free-standing wall. If a steel I-beam is a floor or a roof girder support, flame impingement on the I-beam will expand the beam, and it will push against the block wall. Heated to 1,000°F, a steel member will expand 9½ inches per 100 feet of length. At temperatures above 1,000°F, steel will start to soften and fail, depending on the load.

Forcible Entry

Each storage unit has a lightweight metal accordion roll-up door that the renter secures with his own lock. The door has a metal hasp that the lock secures to a hasp on the door frame. Sometimes it is easier to cut the door hasp than the lock, especially if a renter has installed an expensive, case-hardened “hockey puck” lock. Don’t wear down the aluminum oxide blade cutting these locks when it would be easier to cut the metal hasp, especially if you have to open many roll-up doors.

If the door or the door’s tension mechanism is warped from the fire’s heat, the burning contents are wedged against the door, or a storage unit has fully involved fire within, you must cut the door. The demolition rotary saw with an aluminum oxide blade will suffice. When cutting, do not stand directly in front of the door, but cut from the side in case a fireball should erupt or the contents explode. For roll-up doors that are not distorted from heat or fire, cut the lock or the hasp. Always have a charged hoseline ready when opening up a storage unit involved in fire (photo 9).

If enough fire personnel are on the scene with multiple saws, cut a large opening to numerous fire-involved unit doors. You can also use a triangle cut as a quick opening to knock down the fire. For overhaul, expand and square off the cut. These light-gauge metal accordion doors are easy to cut. If the overhead door is off its tracks, it is very difficult to cut because the saw blade’s pressure will just push the door inward. Be aware of the razor-sharp edges from the cut metal door. Firefighters should never enter these burning units.

(7) Unprotected wood joists support this second-floor platform in a unit that was not affected by the fire.
(7) Unprotected wood joists support this second-floor platform in a unit that was not affected by the fire.

Overhaul: the Silent Killer

During overhaul, you must wear your mask during the entire operation. Unknown, deep-seated burning contents produce a heavy concentration of carbon monoxide and a toxic soup of other gases.

Structural overhaul involves checking for fire extension within the structure by opening up ceilings, walls, floors, or voids in and around the fire perimeter. These voids must be defined and opened up to check for fire extension. The common open space by the ceiling between each storage unit or the open cockloft found in two-story buildings is an avenue for extension.

Content overhaul means removing and extinguishing any smoldering contents. I recommend hydraulic overhaul at these deep-seated contents fires, possibly using a fixed monitor, thereby avoiding unnecessary firefighter exposure to the toxic smoke by-products. With today’s constant budget restraints on the fire service, avoid unnecessary bunker gear contamination when operating at stubborn deep-seated, smoldering fires.

(8) The effect of fire on the second-floor platform. <i>[Photos courtesy of the Orange County (CA) Fire Authority.]</i>
(8) The effect of fire on the second-floor platform. [Photos courtesy of the Orange County (CA) Fire Authority.]

Content overhaul at a self-storage building fire is labor intensive. Relieve those firefighters who operated during the fire once the fire is under control. Firefighter injuries occur more frequently during overhaul because of exhaustion. During hot humid weather, ensure that firefighters are rotated frequently and are kept constantly hydrated to avoid overheating body core temperature. Heat stroke is life-threatening. I cannot emphasize enough-wear your mask throughout the whole operation. The burned-out contents are nothing more than a pile of smoldering rubbish (photo 10). As the overhaul stage begins, it has the potential to change into a hazmat incident if unknown liquids found are leaking or other hazardous items are uncovered amid the deep-seated smoldering rubble. Keep in mind the possible contamination of firefighter bunker gear.

At a recent fire in Putnam County, New York, firefighters used a small excavator to gingerly remove the deep-seated burning contents from the storage units. Once they removed the contents, they wet them down with a hose stream and constantly monitored them for hazardous chemicals or materials. This can be a long, drawn-out process, depending on the amount of burning contents and the space available for removed contents. Be careful not to bury the hoselines with rubble. Open rubbish containers brought to the site can be used to store removed contents when space is limited.

Many fire departments throughout the United States have a protocol for a hazmat unit response to self-storage facility fires based on past fire incidents involving the presence of toxic chemicals and materials. The hazmat officer and the safety chief must carefully monitor the incident. The smoke plume will also be monitored along with the water runoff. If a toxic smoke plume is traveling toward a populated area, the IC will communicate to the public to close windows and shelter in place or will initiate an immediate evacuation of that affected area (photo 11).

(9) When cutting or opening the overhead door, stay to the side and have a charged hoseline ready. When operating a hoseline, be prepared for the possibility of a violent flashover or the explosion of unknown contents. [Photo courtesy of the Spokane (WA) Fire Department.]
(9) When cutting or opening the overhead door, stay to the side and have a charged hoseline ready. When operating a hoseline, be prepared for the possibility of a violent flashover or the explosion of unknown contents. [Photo courtesy of the Spokane (WA) Fire Department.]

Operations

The units’ unknown contents are of major concern when operating at a fire in a self-storage facility. Any information the storage center office or personnel at the facility provide is invaluable. What types of businesses are renting the space, and what is their location? This would give the IC an idea about what possibly could be stored. A pest control company might store pesticides, or a pool maintenance company might possibly be storing chlorine (Table 1).

Locating the seat of the fire might be hampered by a heavy smoke condition and the darkness of night obscuring visibility. The thermal imaging camera might be helpful in locating the fire. Do not open up fully involved storage units until you have a viable water supply and charged hoselines in position. If apparatus access is limited or you need to stretch numerous hoselines, consider a portable manifold. The strategy is to define the fire perimeters of the free-burning, the smoldering, and the clean areas. Using a 1¾-inch hoseline with a solid stream nozzle and a solid stream 15⁄16-inch tip for extinguishment provides versatility, a safe operating distance, and good stream penetration. The average storage unit size is 100 to 150 square feet, the size of a small bedroom. Once the surface fire is knocked down, the deep-seated fire in the contents will not be completely extinguished and will continue to smolder, eventually lighting up until the burning area is uncovered and wet down.

When operating at storage buildings that have back-to-back storage units on two separate access roads, ensure you are not operating opposing hoselines.

(10) Deep-seated smoldering content is emitting a toxic soup of gases. Wear your mask! [Photo courtesy of the Spokane (WA) Fire Department.]
(10) Deep-seated smoldering content is emitting a toxic soup of gases. Wear your mask! [Photo courtesy of the Spokane (WA) Fire Department.]

Rural Operations

The IC must recognize the time needed for the arrival of fire personnel and to set up a viable water source. In rural areas, recognize the potential for a well-advanced fire on arrival because of delayed notification and the remote location. Arriving at a well-advanced fire with insufficient fire personnel could have dire consequences. Under these circumstances, it is prudent to stand fast until you have evaluated the fire incident, have a viable water source ready and available, and have adequate fire personnel on the scene.

In rural areas without a hydrant grid system, firefighters must take into account the minimum time needed to set up a viable water source, since they may rely on tankers or drafting from a water source. A heavy amount of fire on arrival might be beyond the capability of hoselines. Consider an exterior attack using high-caliber streams.

(11) Monitor the wind direction of a toxic plume. Consider whether to evacuate civilians or to shelter in place. At night, the smoke plume’s movement may be more stationary. [Photo courtesy of Escambia County (FL) Fire and Rescue.]
(11) Monitor the wind direction of a toxic plume. Consider whether to evacuate civilians or to shelter in place. At night, the smoke plume’s movement may be more stationary. [Photo courtesy of Escambia County (FL) Fire and Rescue.]

Apparatus placement is critical when setting up at a well-advanced, fast-moving fire. Take the time to evaluate the best location and operate from the windward side, away from the smoke, if all possible.

Author’s note: Thanks to the Spokane (WA), Colorado Springs (CO) , and Waterbury (CT) Fire Departments and the Orange County (CA) Fire Authority for sharing their past fire incidents, photos, and knowledge.

JOSEPH T. BERRY, a 31-year veteran of the Fire Department of New York (FDNY), retired as a lieutenant in 2002. He was a firefighter with Engine 1 and Ladder Company 24. Promoted to lieutenant in 1983, he served with Engine 73 and then Ladder 42 until his retirement. Berry served on an FDNY committee that revised the probationary firefighter’s manual and the standard operating procedures for firefighting in tenements, brownstones, wood-frame buildings, and lightweight residential construction. He has written numerous articles on building construction and firefighting. Berry was a consultant for Titan Corporation/Department of Homeland Security.

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Self-Storage Fires Preplan Recommendations

Note: The below items are derived from the author’s experience and from various state and local storage facility fire codes. Applicable local, municipal, and state fire codes take precedence when they conflict with the recommendations below.

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