Fire Studies: Vacant Building Fires

Not until you arrive at an incident and do a proper size-up can decisions be made on the appropriate strategy and tactics to employ. Decision-making at vacant buildings is no exception. In fact, they often demand greater attention because of the possibility of life-safety concerns for firefighters as well as for squatters and possible structural defects.

Case study investigations of the National Institute for Occupational Safety and Health (NIOSH) of firefighter deaths at incidents in vacant structures include:

• A firefighter died after being crushed by a roof collapse in an abandoned building. Firefighters initially used a defensive fire attack to extinguish much of the fire that was showing from the second-floor windows on arrival. After that, crews entered the second floor to perform overhaul operations. During overhaul, the roof collapsed onto the second floor. When the victim was located, he was unconscious and unresponsive. He was removed from the structure and transported to a local hospital, where he was pronounced dead.
• Two career firefighters who were working inside of an abandoned commercial structure died when the roof collapsed during suppression operations of a rubbish fire. The structure was abandoned for at least five years. Nineteen other firefighters were hurt as a result of the collapse.
• A captain died after being trapped by the partial collapse of the roof on an abandoned wood-frame dwelling that was in a dilapidated condition and was known by residents in the area to be a “crack house.”

In recognizing the dangers of fighting fires in vacant structures, NIOSH issued an alert: “Firefighters are often killed or injured when fighting fires in abandoned, vacant and unoccupied structures. These structures pose additional and sometimes unique risks because of the potential for firefighters to encounter unexpected and unsafe building conditions, such as dilapidation, decay, damage from previous fires and vandals, and other factors, such as uncertain occupancy status. Risk management principles must be applied at all structure fires to ensure the appropriate strategy and tactics are used based on the fireground conditions encountered.”

Vacant building definitions

Every building—inhabited or vacant—goes through various stages of natural deterioration during its lifetime. Proper maintenance of the structure minimizes most breakdowns, whereas little or no maintenance, even in an inhabited structure, results in degradation. (People tend to fix what they can afford to fix and that which inconveniences them.)

Vacant buildings can be categorized into two types: structures that are vacated and await resale (they basically are sound); and structures that have been vacant for a period of time and have been stripped of any contents that would have a resale or scrap value, including piping, toilet and plumbing fixtures, and kitchen cabinets. The latter structure type is empty of furnishings, can become a receptacle for trash, can be in varying states of decay and becomes a death trap for members who respond to fires in them.

The second type of vacant buildings, which are the type that are focused on in this column, frequently are abandoned by owners who don’t want to be found. The cost of demolition of a vacant building far outweighs the value of the property, and the expense to rid the community of the blight that’s created by these structures often is borne by the local government.

A concern of fire departments is the possibility of arson for profit in declining areas: Unscrupulous owners, who realize that they are unable to sell the property, might attempt to take the easy way out of an unprofitable situation. Such fires leave behind shells of buildings that are in various degrees of decay, awaiting insurance settlements. The vacant buildings then become an invitation for trespassers to vandalize the remaining contents and to start additional fires on the property.

Effects of weather

Further damage to these already deteriorated buildings is caused by the weather. Leaking roofs and lack of paint on windows and cornices allow water to attack structural members, which weakens the buildings. Rainwater that enters masonry walls can erode the mortar that holds walls together. Water can freeze between the layers of brick in older buildings, which causes the walls to separate, and that diminishes the walls’ strength.

The problems are compounded when the vacant structure is attached to other buildings. Whether a commercial or residential building, the adjoining properties will be affected. The party wall, or common bearing wall that’s a fire-stop between structures, can break down, and a fire that enters the cockloft or attic can spread to the adjacent properties. This breakdown of the party wall might affect the structure’s load-carrying capabilities, which can cause an early collapse.

The additional weight of firefighters and their equipment, combined with the weight of tons of water that’s used in the extinguishment process, might be too much for the building to bear. Wood that’s rotted because of constant exposure to the weather fails rapidly under fire conditions. Localized collapse is most common, yet major building collapse also can occur.

It must be remembered that once a building enters into this dilapidated condition, deterioration is continual and usually is followed by additional collapse.

Marking vacant buildings

Outward appearance of a building might or might not give signs of neglect and dangerous conditions. The stability of exterior walls doesn’t guarantee the strength of the roof or interior areas. An ongoing size-up or a closer look on the interior must be performed. However, on scene of an incident, there typically isn’t time to perform a thorough investigation of the building’s stability. Size-up will discover some obvious collapse indicators, but smoke conditions and darkness can hide others.

One method of identifying vacant building problems is a routine inspection of the structures and then marking the exterior walls. Markings can entail painting symbols on the front wall or attaching a wooden placard at a specific location to identify and categorize buildings as to their structural stability. Categories can include “Too dangerous to enter,” “Dangers exist/enter only if life is threatened” and “Minor interior damage/entry can be made, depending on fire conditions.”

The vacant buildings are inspected at timed intervals, and if the conditions of the buildings change, the markings are updated to reflect the observed hazards

Although responding firefighters can utilize building placards as part of their size-up, they must realize that a placard is part of the preplanning stage and just one component of the size-up process. Markings must be weighed together with information that’s available on scene. Having a building marked as “Minor interior damage/entry can be made, depending on fire conditions” doesn’t mean that an offensive attack can be made. Changes might have occurred between the time that the vacant building was marked last with placards and the time of the fire.

Firefighting considerations

Some experts believe that firefighters never should fight a vacant building fire in an offensive mode. Their point is that no vacant building is worth the life of a firefighter. However, all buildings must be sized up and the factors must be weighed as to the best method of protecting life while controlling and extinguishing the fire. It isn’t realistic to automatically fight every vacant building fire in a defensive mode.

The incident commander (IC) must apply common sense while controlling the aggressiveness of the firefighters to ensure a safe operation. The lessons learned in fighting dwelling fires with an offensive-exterior attack can be used at a vacant building fire. Numerous openings that can’t be controlled might create multiple flow paths that will supply oxygen to the fire.

Conditions will dictate whether the offensive-exterior attack can be followed by an offensive-interior attack. If deemed safe by the department safety officer, crews can enter the vacant building to perform a primary search and to complete the extinguishing process. If interior conditions are deemed to be unsafe, then a defensive attack should be used to extinguish the fire.

Some cities that have a large number of vacant/abandoned properties now are reassessing the practicality of offensive attacks in these structures.

Attempts to seal vacant buildings by local, state and federal agencies involve closing door and window openings with wood, tin or masonry. (These efforts often are foiled, and illegal entry continues.) Under fire conditions, these closed doors and windows must be opened to ensure adequate ventilation for firefighting efforts. The removal of sealing material from window and door openings can be time-consuming and challenging.

An exterior attack on vacant building fires that are beyond the initial stages and/or don’t involve occupants can be a successful tactic. Unlike occupied structures that contain valuable furnishings, water damage isn’t a concern in vacant properties. The only consideration regarding water is the weight that the water adds to the live load in the building.

The bottom line: Any fireground problem that’s normally encountered is accentuated in a vacant structure. Fires in vacant buildings cause more firefighter injuries and deaths than other structural fires. The IC must control the natural aggressiveness of the firefighters to ensure a safe operation.