This article is the result of three years of research and study of line-of-duty deaths (LODDs) that occur in structure fires. One of the findings is that using standard tactics on nonstandard structures is resulting in firefighter disorientation, the loss of direction because of the inability to see in a structure fire. This problem has plagued and challenged the fire service for decades.

The research in this article is based largely on National Institute for Occupational Safety and Health (NIOSH) data. Seventeen cases of disorientation that resulted in 23 firefighter fatalities were reviewed from the following perspectives: smoke and fire conditions found on and after arrival, the strategies and tactics used, and the actions taken in the structures. Nine major similarities that may help to solve the firefighter disorientation problem were identified.

The following was observed in the 17 disorientation fires reviewed:

• The incidents occurred in an enclosed structure (100% of cases).

• Companies encountered nothing-light, moderate, or heavy smoke-on arrival (94% of cases).

Companies implemented an aggressive interior attack (100% of cases).

Companies encountered prolonged zero-visibility conditions (PZVC) (100% of cases).

Companies experienced handline separation (100% of cases).

• Companies lost company integrity (100% of cases).

• Companies experienced disorientation (100% of cases).

• There was no operating sprinkler system (88% of cases).

• There was a disorientation sequence (100% of cases).


An initial examination of each structure revealed that the structures had little in common-they varied in occupancy type, construction type, size, and age. However, when viewed from a different perspective, it was determined that in 100 percent of the cases the structures had an enclosed design-that is, the structure had very few windows or doors in relation to its size. The enclosed structures in which disorientation occurred also included basements and high-rise hallways. Some structures are enclosed by architectural design, others as the result of having been altered after construction. The preexisting windows and doors in the altered structures typically were enclosed by wooden boards, plywood sheeting, concrete block, gypsum board, brick and mortar, steel burglar bars, or metal sheeting.

(1) An extremely dangerous Opened Structure with a Basement. (Photos by author unless otherwise noted.)

To categorize structures according to their associated level of risk-Dangerous or Extremely Dangerous-structures were classified as Opened Structures and Enclosed Structures.

Opened Structure

An Opened Structure has windows and doors of sufficient number and size to provide for prompt, adequate ventilation and emergency evacuation. Disorientation usually does not occur in this type of structure. These structures, usually of a small to medium size, can be of any occupancy type, construction type, or age.

(2, 3) Although it can be dangerous, an Opened Structure allows for prompt ventilation and emergency evacuation.

However, certain larger subdivided structures also can fit into the Opened Structure category as long as firefighters can promptly ventilate and evacuate in an emergency. Examples are a one- and two-story multifamily dwelling on a slab foundation, such as an apartment building or a condominium. Although these structures pose dangers, firefighters understand the hazards and safely manage the risks associated with these structures on a daily basis.


Enclosed Structure

Disorientation and firefighter fatalities repeatedly occur in an Enclosed Structure. These structures can be any occupancy type, construction type, size, or age; they can be occupied, unoccupied, or vacant. Four types of Enclosed Structures, identified and classified according to a simple description of their appearance, were defined:

4-10) Enclosed Structures can be of any occupancy type and can be occupied or unoccupied. [Photos 9-11 by Chief Bobby Halton, Coppell (TX) Fire Department.]

Opened Structure with a Basement. This is an extremely dangerous structure that has windows or doors of sufficient number and size to provide for prompt ventilation and emergency evacuation from grade, but not basement, level.


Enclosed Structure. This is an extremely dangerous structure in which there is an absence of windows or doors of sufficient number and size to provide for prompt ventilation or emergency evacuation.


Enclosed Structure with a Base-ment. This is an extremely dangerous type of structure in which there is an absence of windows or doors of sufficient number and size to provide for prompt ventilation and emergency evacuation from grade or basement levels.


High-Rise Hallway. This is an extremely dangerous enclosure above grade level in which there is an absence of windows or doors of sufficient number and size to provide for prompt ventilation and emergency evacuation.



The study results provided a clearer understanding of the circumstances in which fatal injuries were sustained. Firefighter fatalities were the results of burns, asphyxiation, or trauma attributable to disorientation but secondary to the following life-threatening events:


• disorientation secondary to PZVC,


• disorientation secondary to extreme fire behavior events,

• disorientation secondary to backdraft, and

(11) Many Enclosed Structures are enclosed simply by architectural design.

• disorientation secondary to collapse.

Disorientation Secondary to PZVC

Firefighter safety depends on understanding the difference between zero visibility and prolonged zero visibility. Zero-visibility conditions are heavy and blinding smoke conditions that do not persist longer than 15 minutes. These visibility conditions are not considered life threatening to the trained firefighter dressed in full personal protective equipment that includes self-contained breathing apparatus. Zero-visibility conditions are commonly encountered at smaller-size Opened Structures, which can be promptly ventilated in about 15 minutes or less. This type of zero-visibility condition is very common; firefighters everywhere are familiar with it. PZVC, on the other hand, are heavy and blinding smoke conditions that last at least 15 minutes or longer. In one Enclosed Structure incident, heavy smoke conditions lasted seven hours.

(12) Basements present extreme hazards for firefighters. Always look for basement windows during the initial size-up.

PZVC affect firefighters much differently than zero-visibility conditions. In regards to breathing time, 15 minutes is the approximate amount of breathing time a working firefighter can expect while on the most commonly used 30-minute rated self-contained breathing apparatus. If firefighters cannot ventilate or evacuate the structure within 15 minutes or less, a potential life-threatening condition would exist if disorientation were to occur.

(13) The small basement window at the A/B corner and the flight of steps leading to the front door may be the only indications of a basement.

In Phoenix, Arizona, prolonged zero visibility caused several firefighters in an Enclosed Structure (grocery store) to become disoriented. One firefighter, executing an aggressive interior attack with his crew, became separated from the hand-line and ran out of air trying to evacuate.

In St. Louis, Missouri, two firefighters without a handline and low on air attempted a rescue on the 21st floor of an apartment high-rise. They quickly became disoriented from the thick smoke after entering the hallway. One firefighter was able to reach the safety of the stairwell, but the second one ran out of air and needed rescue. Heavy smoke causes firefighters to lose vision during this type of disorientation, which can also be caused by other means. For example, in Kansas City, Missouri, smoke and the production of conversion steam during firefighting efforts caused the loss of vision. In Fall River, Massachusetts, in addition to heavy smoke, loss of visibility was caused by a powdered dye that created a wet black film that covered firefighters’ masks.

Prolonged zero visibility also deceptively develops at different rates of speed. In a cold storage warehouse in Worcester, Massachusetts, PZVC, caused by thick black smoke, set in suddenly after arrival. The sudden change of conditions caused firefighters to lose sight of one another and of their surroundings as they unsuccessfully tried to reach the safety of a stairwell. PZVC may be encountered on arrival, suddenly after arrival, and sometimes long after arrival. In a Kansas City paper warehouse fire in which light smoke was showing on arrival, PZVC set in after 52 minutes, causing disorientation and the line-of-duty death of one officer.

Disorientation Secondary to Extreme Fire Behavior

Extreme fire behavior encompasses a wide variety of fire-related events including rollover, flameover, and others difficult to describe because of the lack of awareness or experience of the reporting firefighter. The sudden ignition of all the flammable gases off-gassed during the decomposition of the burning and superheating of the materials is flashover. In disorientation secondary to flashover, the firefighter is suddenly engulfed in fire, as the force of the flashover causes the firefighter to be separated from the handline as vision and orientation are lost. Instead of heavy smoke causing the loss of vision, as in PZVC, the fire causes the loss of visibility in disorientation secondary to flashover. A firefighter will not survive the severe thermal exposure in this life-threatening event if exposed to the intense heat for more than a few seconds; the best option is to immediately exit the structure.

Although disorientation secondary to flashover may occur in any size structure, the sudden loss of vision coupled with the sudden exposure to extreme temperature has on occasion made prompt evacuation, even from small rooms and structures, impossible for some firefighters. This occurred at three incidents: at an Opened Structure with a Basement in a single-family dwelling in Cincinnati, Ohio; at an Enclosed Structure involving a custom auto shop in Porter, Texas; and at a two-story Enclosed Structure with a Basement in a townhouse unit measuring 19 feet by 33 feet in Washington, D.C.

(14) This extremely dangerous Enclosed Structure with a Basement is enclosed by design and security bars, making prompt evacuation impossible.

In high-rise structures, disorientation secondary to extreme fire behavior, described by survivors as a blowtorch-like flashover, claimed the lives of firefighters in New York City. This type of disorientation occurs instantaneously if wind is blowing into the unit on fire as the hallway door leading to the unit is opened. Incidents of this nature have also occurred in Chicago, where eight firefighters suffered burn injuries in one incident. In Houston, Texas, high winds pushed the fire into a hallway as two captains were attempting to evacuate. They were also hampered by PZVC and became entangled in handlines, which caused one of the officers to become even more disoriented.

Disorientation Secondary to Backdraft

Backdraft is an explosion caused by a smoldering fire in which smoke (combustible gases hot enough to ignite but lacking sufficient oxygen) accumulates in a confined space. Sudden introduction of oxygen to the smoldering fire initiates the explosion, which can generate deflagrating forces. In disorientation secondary to backdraft, the firefighters are hit by a violent blast of heat and pressure, causing them to become disoriented and separated from the handline. Like flashover, a backdraft may engulf the firefighter in fire. Fire or fire and smoke cause the loss of vision in these cases. Three such incidents occurred. Two were within the cases studied: one at an Opened Structure with a Basement (a single-family dwelling) in Ohio and another that involved 10 firefighters at an Enclosed Structure with a Basement (an auto service center) in Chicago. The third, in Memphis, Tennessee, occurred after the study was concluded. It was at an Enclosed Structure (a department store).

Disorientation Secondary to Collapse

Disorientation secondary to collapse is associated with collapses of floors and roofs. In floor collapses, unsuspecting firefighters become disoriented after falling through the first floor into the involved basement. Fire or smoke typically causes loss of vision; if the firefighters are not promptly removed from the basement, they will die.

(15) To rule out the possibility of an involved basement, conduct a 360° walk-around during the initial size-up.

In roof collapses, firefighters searching for the seat of the fire, attacking the fire deep in the structure, or evacuating may become disoriented and trapped. In one case, as firefighters were evacuating, a collapse of a wooden bowstring truss roof trapped a fire captain in an Enclosed Structure (a warehouse) in Los Angeles, where PZVC had already set in. One of the most common causes of the floor and roof collapses that led to disorientation in the study was the fire’s weakening the lightweight wooden or steel trusses supporting the floor or roof, causing them to fail. One cardinal safety rule of firefighting is that firefighters should not be on or under a truss floor or roof when fire is attacking the trusses, since a collapse can occur at any time. However, in reference to roofs, a major part of the overall problem has been that firefighters on occasion were not able to see the fire impingement on the trusses through the dense smoke or suspended ceiling tiles they encountered.



Firefighters experienced handline separation or encountered tangled handlines in 100 percent of the cases examined. Light smoke showing on arrival may have given one firefighter the impression that a handline was not necessary, but it was needed when zero-visibility conditions set in. In other instances, the intense pressure caused by flashovers and backdrafts caused firefighters to become separated from the handline. In one case, handline separation occurred when a firefighter fell through a floor and into an involved basement. In two other cases, the handline was unintentionally removed from the structure before it was determined that all firefighters had evacuated.

(16) A slope in the terrain along the foundation line may indicate the presence of a basement.

Tangled handlines or “spaghetti” that formed as extra hose was advanced into the structure to allow companies to reach the deeper portions of the structure confused firefighters evacuating in zero visibility in many instances. Regardless of how the separation or tangled handlines occurred, whether intentional or unintentional, the outcome was the same-confused firefighters or firefighters wandering aimlessly, with no visibility or lifelines to the exterior, in a structure that had very few windows or doors for evacuation.

In all of the cases studies, company integrity, a firefighter’s safety net, was lost. In one incident, a fire officer was not with a crew or a buddy while inside the structure. In another case, company integrity was lost when a company anxiously walked up a stairwell to start a search for disoriented firefighters. In another instance, company members became separated during the interior firefight. In addition, in 10 cases (51%), companies lost integrity while evacuating from the building.


Thinking back on the fires you responded to in the past, you perhaps could recall several Enclosed Structure fires in which an aggressive interior attack safely extinguished the fire. The only reason you safely exited the structure and did not become disoriented was that you luckily avoided a step in the disorientation sequence.

(17, 18) Based on his initial size-up, in which he determined that this residential structure was an �Enclosed Structure,� District Chief Richard Johnson of St. Petersburg (FL) Fire & Rescue ordered an evacuation. Note the plywood sheeting used to enclose the windows. Within two minutes of evacuating, smoke conditions changed drastically, resulting in a defensive operation. Johnson had attended the �Understanding and Solving Firefighter Disorientation� class at FDIC 2005 on April 13. This fire occurred on April 21. (Photos by Lt. Jeff Satmary, St. Petersburg Fire & Rescue.)

A sequence of events that usually unfolds in a structure without an operable sprinkler system caused firefighter disorientation in all of the incidents studied, resulting in 23 firefighter fatalities. In general, the sequence that leads to fatalities or serious injuries involves the following steps or scenario:


• fire in an Enclosed Structure with smoke showing;

• an aggressive interior attack;

• deteriorating conditions such as PZVC, flashover, backdraft, or collapse;

• handline separation or tangled handline encountered;

• disorientation; and

• serious injury or firefighter fatality.

In a fire in an Enclosed Structure with smoke showing, the arriving fire company immediately initiates an aggressive interior attack to search for the seat of the fire. During the search, the seat of the fire cannot be located and conditions deteriorate-heat, smoke, and prolonged zero visibility. As companies attempt an emergency evacuation because of the deteriorating conditions, they become separated from the handline or they encounter entangled handlines. Disorientation occurs as firefighters exceed their air supply, are caught in flashovers or backdrafts, or are trapped by the collapse of the floor or roof. When firefighters in these conditions are not located quickly enough, fatalities or serious injuries result.


A lack of knowledge about the extreme danger posed by Enclosed Structures and the Disorientation Sequence is at the root of the fire service disorientation problem. In addition, firefighter fatalities related to smoke inhalation, burns, or trauma attributable to disorientation are directly linked to the four types of Enclosed Structures identified above. Disorientation has occurred in Opened Structures, but only occasionally. In one case, disorientation secondary to flashover occurred in an Opened Structure (a single-family dwelling) in Florida, as documented in NIOSH Firefighter Fatality Investigation Report F2000-44.


It is well known that established standard operating procedures in U.S. fire departments call for a quick and aggressive interior attack, also referred to as an “offensive strategy,” for any fire structure safe to enter. One fireground condition included in an officer’s initial size-up is the amount of smoke showing from the structure on arrival. Light, moderate, and heavy smoke are common smoke conditions under which an officer would initiate a quick interior attack to locate and extinguish the seat of the fire or to conduct a primary search. Based on this study’s results, however, these were the same smoke conditions found on arrival at 94 percent of the Enclosed Structure fires that ultimately resulted in firefighter disorientation. It, therefore, was an incorrect interpretation of the size-up factors that formed the basis for the decision to make an aggressive interior attack in 100 percent of the cases that led to unfavorable outcomes.



Analysis of the initial size-ups used by officers during the disorientation fires showed that the size-ups were conducted using traditional size-up factors that related to Opened Structures and their associated risks. The traditional size-up includes a quick evaluation of the type of occupancy, type of construction, size, and age of the structure and the amount of smoke or fire showing on arrival. These size-up factors have long served as reliable indicators of the hazards of construction and contents and of the life hazard present and are widely recognized and used in the fire service. However, when officers applied the Opened Structure size-up to the Enclosed Structure fires, it repeatedly resulted in disorientation, serious injuries, and firefighter fatalities.

Factors such as light, moderate, or heavy smoke showing from an Opened Structure may mean that conditions are safe enough to initiate a fast and aggressive interior attack. However, results in 100 percent of the cases studied indicate that these exact smoke conditions showing from an Enclosed Structure have an opposite meaning. Light, moderate, or heavy smoke showing from an Enclosed Structure is, in fact, an indication of an extremely dangerous situation that requires a more cautious, deliberate, and calculated approach. This applies to the method of locating the seat of the fire, approaching the seat of the fire, and conducting a primary search.

In retrospect, one reason for the unfavorable outcomes at Enclosed Structures has been that Enclosed Structures, in all of their forms, were not officially recognized as “types” of structures that would indicate a severe risk of firefighter disorientation.

Further analysis of the traditional strategy and tactics used at the disorientation fires revealed that they, too, were inadequate and unsafe for use on Enclosed Structures. For instance, when considering fires involving an Opened Structure, firefighters without thermal imaging cameras routinely rely only on their senses to help find the fire during heavy smoke conditions. This involves feeling for the heat through firefighting gear and listening for the crackling and popping sounds of a fire as indicators of the fire’s proximity. It also involves using the limited capability of the naked eye to see the glow of the fire through the thick smoke. If nothing is felt, heard, or seen, firefighters will aggressively open walls or ceilings or advance deep into a structure, if necessary, to quickly find the seat of the fire.

Traditional tactics, however, have repeatedly resulted in unfavorable outcomes in Enclosed Structures. Using the traditional tactics has unexpectedly resulted in firefighter disorientation secondary to PZVC when firefighters aggressively searched deep into the structure for fire. These approaches resulted in exposure to backdrafts when the ceiling was forced open as they tried to find the fire. In other cases, these tactics resulted in exposure to flashover as companies aggressively searched for the seat of the fire.

Finally, the traditional tactics resulted in disorientation after floors and roofs collapsed when the fire was not detected above or below the advancing firefighters. Fatalities also occurred when firefighters attempted primary searches when bystanders indicated that “there might be someone inside” and in reality no victims needed rescue. This scenario occurred in Worcester and was repeated in Ohio, Memphis, and Houston.

Another example of different traditional tactical priorities in 14 of 17 cases examined was that primary searches were not required at Enclosed Structures because the structures were vacant or occupants had already exited the structure before firefighters arrived.

In summary, traditional size-up and strategy and tactics used at Enclosed Structure fires performed poorly. This was further indicated by the results of 12 of 17 fires studied (71 percent) in which the strategy was changed from an offensive to a defensive operation, but only after firefighter fatalities or serious injuries had occurred.


Now that we have an idea of where, how, and why disorientation occurs, what are we going to do about it? We cannot continue to allow firefighters to use an aggressive interior attack on every structure fire or to search for the unknown location of the fire when we know it may be ineffective or unsafe in many cases. Preventing firefighter fatalities, therefore, requires controlling the risk. We can accomplish this in part by understanding that Opened Structure fires call for offensive size-up, strategy, and tactics, whereas Enclosed-Structure fires call for size-up, strategy, and tactics that manage the greater risk. This necessitates conducting disorientation prevention training to provide firefighters with an understanding of the hazards associated with Enclosed Structures. This training should also incorporate all pertinent national standards and include the following:

• the recognition and identification of Opened and Enclosed Structures,

• the hazards of construction (lightweight wood and steel trusses and unprotected steel),

• the hazards of PZVC,

• the means of identifying preflashover and prebackdraft conditions,

• the types of disorientation,

• the disorientation sequence,

• instruction in an enclosed structure SOG,

• safe ventilation that does not initiate flashover or backdraft,

• the safety equipment required,

• safe breaching techniques, and

• a review of fires in which disorientation caused injuries and fatalities.

Safety Equipment

To safely manage the risk at Enclosed Structure incidents, among the equipment needed is full personal protective equipment (PPE) and SCBAs with PASS devices, portable radios, thermal imaging cameras, and equipment for emergency breaching and shoring operations. It will also call for safety directional arrows for handlines and company identification markings that will prevent firefighters from repeating unsafe actions caused by misreading handlines. These types of mishaps occurred during PZVC in Fall River, San Antonio, Kansas City, Los Angeles, Houston, and Phoenix and included (1) tracing handlines back to the nozzle during an evacuation, (2) confusion caused by tangled handlines, and (3) following another handline into a different portion of a building.

Remember that your risk goes up as the amount of safety equipment decreases and that you will have to reduce your involvement or alter your tactics and exposure to potential hazards accordingly. Even if all of the recommended equipment is not immediately obtainable, simply teaching firefighters to identify Enclosed Structures and to understand and avoid their hazards will help to prevent firefighter fatalities at little to no cost. This is something every fire department in the country can easily do to prevent fatalities.



The following are two essential tactics for use in Enclosed Structures. The first, Cautious Interior Assessment (CIA), is a process whereby the first engine company enters the Enclosed Structure with a thermal imaging camera (TIC) and charged handline to look into the structure to locate the seat of the fire. This company is backed up with an established water supply and an engine company, also with a TIC and a charged line, standing by at the initial point of entry. After the seat of the fire is located-and based on the interior assessment-the officer will decide whether to initiate an aggressive interior attack from the original point of entry, a short interior attack from a different side of the structure, or a defensive attack.

The second tactic, a Short Interior Attack (SIA), involves advancing handlines to the seat of the fire using the shortest distance from the exterior. This may be accomplished by opening existing enclosed windows or doors or by breaching to open exterior or interior adjoining walls. If breaching is not safe or cannot be accomplished in a timely manner, a defensive attack should be made. Initiating a short interior attack increases safety by minimizing the distance between the exterior and the seat of the fire, which does the following:

• maximizes the efficiency of the air supply in SCBAs,

• helps maintain company integrity,

• prevents handline separation,

• minimizes the formation of “spaghetti,”

• avoids exposure to flashover,

• avoids exposure to backdraft,

• avoids exposure to collapse, and

• prevents disorientation.

Most importantly, using short interior attacks may significantly increase the chance of a successful rapid rescue of a downed firefighter simply because of the shorter distance needed to reach and remove the firefighter to the exterior.

• • •

Evaluate the Enclosed Structure Standard Operating Guideline periodically from the perspectives of safety and effectiveness to determine if the anticipated results are being obtained. If necessary, make adjustments to ensure that firefighters are following the safest procedure possible. Consider Enclosed Structures as structures with the highest degree of risk. Remember: If you cannot promptly ventilate or evacuate it and if it has no sprinkler system, it is an extremely dangerous Enclosed Structure that has been taking firefighters’ lives for decades. Protect your firefighters by implementing a risk-management policy, and reduce your risk by developing a safe Enclosed Structure SOG for your department. Firefighters must know the reality. The potential for Enclosed Structure fatalities is tremendous in every community. Sadly, the Enclosed Structure incidents continue. Since the conclusion of the Firefighter Disorienta-tion Study in the summer of 2002, 20 more U.S. firefighter fatalities have occurred in 13 more Enclosed Structure fires in large and small and volunteer and career departments. Act now to prevent any additional fatalities.

WILLIAM R. MORA is a 30-year veteran and captain and former training officer for the San Antonio (TX) Fire Department. He is active with the National Fallen Firefighters Foundation. He has a degree in business administration and is the author of “The United States Firefighter Disorientation Study.”

The risk with Enclosed Structure fires is controlled before the emergency by programming the SOG to prevent exposure to the potential Enclosed Structure hazards. Specifically, the risks, again, are disorientation secondary to flashover, backdraft, collapse of floors or roofs, and PZVC that cause firefighters to run out of air. Also, part of the risk is managed during the emergency by assessing interior conditions and choosing the safest tactic to achieve the best possible outcome. However, never hesitate to go defensive on these extremely dangerous structures. To control the risk associated with Enclosed Structure incidents, fire departments can draft and implement Enclosed Structure Standard Operating Guidelines (ESSOGs) custom tailored to their department’s capability. The goal of an ESSOG is to prevent firefighter disorientation and fatalities while attempting to extinguish Enclosed Structure fires. To achieve the best possible outcome, incorporate flexibility into the guideline. Many of the lessons learned from the 17 disorientation fires studied, and others, are included in the example ESSOG and in the list of recommended Enclosed Structure tactics below. When implementing an ESSOG, as with any other fireground procedure or operation, incorporate all sound firefighting principles and national standards, including the incident command system.

When Is the ESSOG Used?

The ESSOG is used when smoke from an Enclosed Structure is showing on arrival, the location of the seat of the fire is unknown, and no life hazard is present. When safe, the attack will use the shortest distance from the exterior. This simple philosophy pertains equally to all types of Enclosed Structures. To illustrate, the following is an explanation for managing the risk at a large single-story warehouse that is an Enclosed Structure:

As part of the initial size-up, ensure that there is no basement, then cautiously assess interior conditions and the fire with a thermal imaging camera (TIC). If safe to do so, initiate an attack into the structure from the original point of entry. However, if conditions, such as narrow aisles, a cluttered interior, or long distances, make it unsafe to advance into and promptly evacuate the structure, initiate a short interior attack from another side of the structure. If, during the assessment, conditions appear unsafe-there are signs of preflashover or prebackdraft or there is a large, uncontrollable content fire or a fire in the roof that may compromise structural integrity-withdraw the company and call for a defensive attack.

When Is the ESSOG Not Used?

The ESSOG is not used when a genuine primary search is required. During these rescue situations, and as with any Opened Structure, conduct the search with a TIC and a charged handline to simultaneously attack the fire. The rescue action plan must be more calculated: Consider and attempt to avoid the hazards associated with Enclosed Structures.

The following example of an ESSOG outline is offered for your consideration and use as a model to develop an ESSOG that will be unique to your department.


This guideline is for Enclosed Structure fires when smoke is showing on arrival, the seat of the fire is unknown, and no life hazard is present. It is a flexible guideline and, for safety and task predictability, is implemented on the sequence of company arrival.

1. The first-arriving officer-identifies the Enclosed Structure:

A. During the initial size-up, identifies the building as an Enclosed Structure.

B. Considers the need for a primary search.

C. After a brief investigation, describes the structure’s size, occupancy, and conditions in the initial report.

D. When possible, determines the location of the fire from the owner, manager, or tenant.

E. Transmits to implement the ESSOG and describes the type of enclosed structure involved.

2. The first-arriving engine company-carries out cautious interior assessment (CIA) as the fire apparatus officer serves as accountability:

A. Encircles the structure to determine existence of a basement.

B. Selects a point of entry.

C. Lays and charges a handline.

D. Positions next to the point of entry with TIC.

Note: The CIA is conducted after the second engine company is in position at the point of entry and the supply line is charged. The company always works within the limitations of the TIC. The distance the company may advance depends on the size of the structure and the conditions encountered but in all cases will be kept to a minimum. When the seat of the fire is located, the officer will decide, based on the size of the contents fire, interior arrangement, structural integrity, and distance to the fire, if an interior attack should be initiated from the original point of entry, if a short interior attack from a different side of the structure will be made, or if a defensive attack will be conducted. Command will also approve the action to be implemented. If an interior attack is initiated, all remaining companies will reinforce the attack as required and coordinated by Command.

3. The second-arriving engine company-serves as RIT or backup company:

A. Lays and charges a second handline from second company.

B. Positions next to the point of entry with a TIC.

C. Monitors radio transmissions between the first engine officer and Command.

D. Reorients, rescues, or backs up the first engine company as needed.

4. The third-arriving engine company-serves as supply, RIT, or backup company:

A. Lays and charges a supply line.

B. Lays and charges a third handline.

C. Positions next to the point of entry with a TIC.

D. Monitors radio transmissions between first engine officer and Command.

5. The fourth-arriving engine company-serves as a flexible engine company:

A. Stages on a hydrant and will provide backup or RIT service at the initial point of entry.

B. When ordered by command, straight lays a supply line to the side of the structure to allow a short interior attack to be initiated.

6. Truck companies (2) and technical rescue team-provide utility control, ventilation, and access support:

A. Closely coordinates ventilation efforts with Command to avoid causing flashover or backdraft.

B. Opens windows or doors as directed by Command.

C. Removes security bars, plywood, gypsum board, or other enclosing material as directed by Command to provide access or means of emergency evacuation.

D. Breaches walls as directed by Command. When possible, will determine from owner, manager, or tenant the most advantageous location to make the breach.

• • •


These size-up factors and strategies and tactics can be used at Enclosed Structure incidents:

1Light, moderate, or heavy smoke showing on arrival is a sign of extremely dangerous conditions that cause prolonged zero visibility, flashover, or backdraft or indicate potential collapse of floors or roofs.

2A layer of light, moderate, or heavy smoke; puffing smoke; and lazy flames seen along the ceiling of an Enclosed Structure are signs of potential backdraft.

3Sparkling or twinkling lights or flames seen through smoke overhead are signs of flashover. Rollover, in which fire rolls along the ceiling over the heads of firefighters, and heavy black smoke with intense heat that forces firefighters to the floor are also signs of imminent flashover.

4Fire showing on arrival is a sign of extreme danger that causes disorientation, flashover, and collapse of roofs and walls.

5If there is doubt whether the building is an Enclosed Structure, the first-arriving officer must err on the side of safety and consider it one by implementing the ESSOG or using Enclosed Structure tactics.

6When the first-arriving officer determines conditions are too poor to conduct a CIA, a defensive operation will be initiated.

7Before conducting a CIA, the officer will encircle the structure to determine if a basement is involved. Some signs of a basement include the presence of basement windows or doors, sidewalk sunlight tiles, or a slope in the terrain along or around the structure’s foundation. Whenever any firefighter determines that a basement is involved, Command and all responding companies must immediately be informed by emergency traffic.

8Firefighters must not be on or under truss floors or roofs when fire exposes the supporting truss, as a collapse can occur at any time.

9Before conducting a CIA in a structure with a suspended ceiling, the officer must have ceiling tiles removed before advancing to verify there is no fire in the ceiling space overhead that may result in roof collapse that may cut off water to the handline and egress from the building.

10For the safety of firefighters, if signs associated with flashover are detected, the officer may order that the nozzle be fully opened to cool the ceiling or affected area.

11Should Command or any exterior company see fire appear from the roof of an Enclosed Structure during a CIA or interior attack, Command will order an emergency evacuation and call for a Personnel Accountability Report (PAR).

12Advanced handlines should be left in position during emergency evacuations so that other evacuating firefighters may use them as lifelines to exit the structure.

13When fire is showing through the roof of an Enclosed Structure and companies do not know the type of roof assembly involved, a defensive attack will be used.

14When possible, truck officers will obtain assistance from owners, operators, or tenants to ascertain the best location to breach a wall. This is not from the perspective of a structural issue, which is addressed/considered by the interior officer during the officer’s interior assessment of conditions (including structural integrity) and as determined visually by the use of a thermal imaging camera. If the interior assessment determines that the roof is involved and in the judgment of the officer there is a collapse potential, we do not breach. The owners, operators, or tenants can be of assistance after the breach is made. They know against which wall(s) heavy stock or machinery is stored, for example. If truck officers or command can remember to ask for this information, they may be able to avoid having to make multiple breaches to finally gain access.

15If an attempt to breach a wall is deemed unsafe by truck officers or cannot be accomplished in a timely manner, Command will be informed. Some signs of an unsafe wall include old age of the structure, smoke seeping through cracks in the wall, a leaning wall, or fire showing at the top of the wall along the roof line.

16If truck companies observe fire venting from vent holes made in the roof or from skylights, they are to immediately inform Command and evacuate the roof.

17All firefighters entering an Enclosed Structure must maintain company integrity and be on or near a handline to serve as a lifeline should conditions deteriorate.

18Fire dispatchers should advise responding companies when occupants have exited the structure and if a basement is involved.

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