Topical Fire Report Series August 2021 | Volume 21, Issue 7

Multifamily Residential Building Fires 

(2017-2019)

These topical reports are 

designed to explore facets 

of the U.S. fire problem as 

depicted through data 

collected in the U.S. Fire 

Administration’s (USFA’s) 

National Fire Incident 

Reporting System (NFIRS). 

Each topical report briefly 

addresses the nature of 

the specific fire or firerelated topic, highlights 

important findings from 

the data, and may suggest 

other resources to consider 

for further information. 

Also included are recent 

examples of fire incidents 

that demonstrate some 

of the issues addressed in 

the report or that put the 

report topic in context.

Findings as reported to the NFIRS

ĵ Each year, from 2017 to 2019, an estimated average of 106,700 multifamily residential 

building fires were reported to fire departments within the United States. These 

fires caused an estimated annual average of 400 deaths, 3,875 injuries and $1.7 

billion in property loss.

ĵ Multifamily residential building fires accounted for 29% of all residential building fires.

ĵ Small, confined fires accounted for 71% of multifamily residential building fires.

ĵ Multifamily residential building fire incidence was slightly higher in the cooler 

months, peaking in January at 10%.

ĵ Cooking, at 74%, was the leading cause of multifamily residential building fires. Of 

these cooking fires, 95% were small, confined fires with limited damage.

ĵ Cooking areas and kitchens (33%) were the primary areas of origin for nonconfined 

multifamily residential building fires.

ĵ In 31% of nonconfined multifamily residential building fires, the fire extended beyond 

the room of origin. The leading cause of these larger fires was other unintentional, 

careless actions (14%). In contrast, 54% of all other nonconfined residential building 

fires (excluding multifamily buildings) extended beyond the room of origin.

ĵ Smoke alarms were present in 64% of nonconfined multifamily residential 

building fires.

ĵ Full or partial automatic extinguishing systems (AESs), including residential 

sprinklers, were present in 15% of nonconfined multifamily residential buildings.

From 2017 to 2019, multifamily residential building fires accounted for an annual estimated average of 106,700 

reported fires. These fires resulted in an annual estimated average of 400 deaths, 3,875 injuries and $1.7 billion 

in property loss.1, 2 In addition, multifamily residential building fires accounted for 29% of all residential building 

fires responded to by fire departments across the nation.3

Multifamily residential buildings include structures such as apartments, town houses, row houses, condominiums 

and other tenement properties. Multifamily residential buildings tend to have stricter building codes than oneand two-family buildings.4 Many multifamily residential buildings are rental properties, and they are usually 

required to comply with more stringent fire prevention statutes and regulations involving smoke alarms and 

sprinkler systems. As a result of the type of building, the more stringent building and code requirements, and 

the fact that more people live in the building itself than in the predominant one- and two-family residences, fires 

in multifamily residential buildings tend to have a different profile than fires in other types of residences.

A major difference in the multifamily residential building fire profile is seen in cooking fires. Cooking was the 

leading cause of 74% of multifamily residential building fires, almost twice that of all other types of residential 

buildings. Multifamily residential buildings also tend to have central heating systems that are maintained by 

professionals instead of homeowners, thus there are typically fewer heating fires from poor maintenance or 

misuse than in one- and two-family dwellings. Also, fire problems related to fireplaces, chimneys and fireplaceNational Fire Data Center

16825 S. Seton Ave.

Emmitsburg, MD 21727

usfa.fema.gov
TFRS Volume 21, Issue 7 | Multifamily Residential Building Fires (2017-2019)

2

related equipment tend to occur less often in multifamily heating fires since multifamily residential buildings generally 

lack these features. Finally, multifamily residential buildings usually have fewer fires caused by electrical problems 

due to construction materials, building codes and professional maintenance.

This topical report is an update to the “Multifamily Residential Building Fires (2013-2015)” (Volume 18, Issue 3) report, 

released in June 2017. As part of a series of topical reports that address fires in the major residential building types, 

the remainder of this report addresses the characteristics of multifamily residential building fires as reported to the 

NFIRS. Comparisons to one- and two-family residential building fires are noted based on analyses from the “One- and 

Two-Family Residential Building Fires (2017-2019)” (Volume 21, Issue 6) topical report.

The focus is on fires reported from 2017 to 2019, the most current data available at the time of the analysis.5 Complete 

or full years of data are required for statistical analyses presented in these topical reports. Although the NFIRS data 

for a calendar year are often reported to the USFA throughout the year, fire departments and or states have until the 

official cutoff date as set forth by the National Fire Data Center to submit their data to the USFA. Typically, this cutoff 

date is July 1 after the end of the previous calendar year. This provides states with ample time to perform data quality 

checks and correct questionable incidents before they are set to released status in the national production database 

and Enterprise Data Warehouse. Once the data are released to the USFA, additional data quality reviews are completed 

before the data are prepared for public release.

For this report, the terms “residential fires” and “multifamily fires” are synonymous with “residential building fires” 

and “multifamily residential building fires,” respectively. “Multifamily fires” is used throughout the body of this report; 

the findings, tables, figures, headings and endnotes reflect the full category of “multifamily residential building fires.”

Type of fire

Building fires are divided into 2 classes of severity in the NFIRS: confined fires and nonconfined fires. Confined building 

fires are small fire incidents that are limited in extent to specific types of equipment or objects, staying within pots, 

fireplaces or certain other noncombustible containers.6 Confined fires rarely result in serious injury or large content 

loss and are expected to have no significant accompanying property loss due to flame damage.7 Nonconfined fires 

extend beyond certain types of equipment or objects. They are generally larger fires resulting in more serious injury 

and larger losses of property and content.

The smaller, confined fires accounted for 71% of the multifamily fires, with cooking fires as the predominant type of 

confined fire (Table 1). Nonconfined fires made up the remaining 29% of multifamily fires. In contrast to one- and 

two-family residences, the relative proportions of confined and nonconfined fires were reversed; nonconfined fires 

accounted for the bulk of one- and two-family building fires (60%), and confined fires accounted for the remaining 40%.

Table 1. Multifamily residential building fires by type of incident (2017-2019)

Incident type Percent

Nonconfined fires 28.7

Confined fires 71.3

Cooking fire, confined to container 63.3

Chimney or flue fire, confined to chimney or flue 0.4

Incinerator overload or malfunction, fire confined 0.1

Fuel burner/boiler malfunction, fire confined 2.0

Commercial compactor fire, confined to rubbish 0.7

Trash or rubbish fire, contained 4.8

Total 100.0

Source: NFIRS 5.0.
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Loss measures

Table 2 presents losses, averaged over this 3-year period from 2017 to 2019, of reported multifamily fires and all other 

residential fires.8 The average number of fatalities per 1,000 multifamily fires was less than half that of the same loss 

measure for all other residential building fires. The average dollar loss per fire for multifamily fires was more than 

half that of the same loss measure for all other residential building fires. In addition, the average loss measures for 

nonconfined multifamily fires were substantially higher than the same loss measures for confined multifamily fires; 

this is to be expected, however, since confined fires rarely result in serious injury or large content loss.

Table 2. Loss measures for multifamily residential building fires (3-year average, 2017-2019)

Measure

Multifamily 

residential 

building fires

Confined 

multifamily 

residential 

building fires

Nonconfined 

multifamily 

residential 

building fires

Residential 

building fires 

(excluding 

multifamily)

Average Loss

Fatalities/1,000 fires 3.1 0.0 10.7 7.5 

Injuries/1,000 fires 29.3 7.0 84.4 23.9

Dollar loss/fire $13,730 $190 $47,300 $20,750

Source: NFIRS 5.0.

Notes:	 1.	Average loss for fatalities and injuries is computed per 1,000 fires; average dollar loss is computed per fire and rounded to the nearest $10.

2. The 2017 and 2018 dollar-loss values were adjusted to 2019 dollars.

When multifamily residential building fires occur

As shown in Figure 1, multifamily fires occurred most frequently in the evening, peaking during dinner hours from 

6 to 8 p.m.9 This peak period was consistent with the major cause of fires, cooking (discussed in the next section, 

“Causes of Multifamily Residential Building Fires”), and accounted for 16% of multifamily fires. Fires then declined 

throughout the night, reaching the lowest point during the morning hours from 5 to 6 a.m.

Figure 1. Multifamily residential building fires by time of alarm (2017-2019)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

11 p.m. - Mid

10 - 11 p.m.

9 - 10 p.m.

1 - 2 p.m.2 - 3 p.m.3 - 4 p.m.4 - 5 p.m.5 - 6 p.m.6 - 7 p.m.7 - 8 p.m.8 - 9 p.m.

12 - 1 p.m.

11 a.m. - 12 p.m.

10 - 11 a.m.

9 - 10 a.m.

1 - 2 a.m.2 - 3 a.m.3 - 4 a.m.4 - 5 a.m.5 - 6 a.m.6 - 7 a.m.7 - 8 a.m.8 - 9 a.m.

Mid - 1 a.m.

2.9 2.5 2.1 2.1

2.6

3.2

3.9

4.4

5.0 5.1 5.3 5.6

6.1

7.1

7.8 7.7

6.8

5.4

4.4

3.5

1.8 1.7 1.5 1.6

Percent of multifamily 

residential building fires

Time of alarm

Source: NFIRS 5.0.

Note: Total does not add up to 100% due to rounding.
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Figure 2 illustrates that multifamily fire incidence was slightly higher in the cooler months, peaking in January at 10%. 

This peak was partially the result of an increase in heating fires. Multifamily fire incidence was lowest during the 

months of June through September reaching a low in August at 7%.

Figure 2. Multifamily residential building fires by month (2017-2019)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

November

December

October

September

August

July

April

May

June

March

February

January

9.9

8.5 8.2

7.7 7.5 7.3 7.5

8.2

8.8 8.8 9.1

8.5

Percent of multifamily 

residential building fires

Month of year

Source: NFIRS 5.0.

Causes of multifamily residential building fires

As shown in Table 3, cooking was by far the leading cause of multifamily fires, accounting for 74% of all multifamily fires.10

The majority of all cooking fires (95%) in multifamily residences were small, confined fires with limited damage. The 

next 7 causes combined accounted for 19% of multifamily fires: heating (4%); other unintentional, careless actions (4%); 

electrical malfunctions (3%); open flames (2%); other heat sources (2%); appliances (2%); and intentional actions (2%).11

Table 3. Leading and secondary causes of multifamily residential building fires (2017-2019)

Cause Percent

(unknowns apportioned)

Cooking 74.4

Heating 3.9

Other unintentional, careless 3.5

Electrical malfunction 2.5

Open flame 2.4

Other heat 2.2

Appliances 2.1

Intentional 2.1

Source: NFIRS 5.0.

The fire cause profile for multifamily buildings was different from the fire cause profile for one- and two-family 

buildings. While the 2 leading causes, cooking and heating, were the same, cooking was a substantially more 

prevalent cause of multifamily fires (74%) than of one- and two-family fires (37%). Heating was a much smaller cause 

of multifamily fires (4%) than of one- and two-family fires (12%). 
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One explanation for the importance of cooking as a cause of multifamily fires may lie in the construction materials, 

building codes and professional maintenance of the buildings. For example, many multifamily residential buildings 

tend to have systems — heating and electrical systems, for instance — that are regularly maintained by professionals. 

As a result, there are fewer fires from lack of maintenance or misuse than in one- and two-family housing. Multifamily 

buildings also have fewer fire problems related to fireplaces, chimneys and fireplace-related equipment than one- and 

two-family residential buildings, since multifamily buildings generally lack this equipment.12

It may also be that confined cooking fires are reported to the fire department more often in multifamily residences. 

While these fires are small and contained, and they do not cause much damage, someone may hear the alarm in 

the complex (if the fire is large enough to activate it) or may smell smoke and notify the building manager or the 

fire department. If it is a newer complex, the alarms are often connected to the building alarm system, and the fire 

department is automatically called. These same small cooking fires in one- and two-family residences may occur as 

frequently but may not be reported as often. As little damage occurs and only the residents hear the smoke alarm 

or smell the smoke, the residents may elect not to call the fire department.

Fire spread in multifamily residential building fires

Three-quarters of multifamily fires (75%) were limited to the object of origin (Figure 3). These fires were primarily 

coded as confined fires in the NFIRS (small, low-loss fires that were confined to noncombustible containers); 93% of 

multifamily fires limited to the object of origin were reported as confined fires. Only 9% of multifamily fires extended 

beyond the room of origin, far fewer than in one- and two-family residences (33%).

Figure 3. Extent of fire spread in multifamily residential building fires (2017-2019)

8.3

Fire spread

Percent of multifamily residential building fires

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0

Beyond building of origin

Limited to building of origin

Limited to floor of origin

Limited to room of origin

Limited to object of origin 74.9

16.1

3.0

5.4

0.6

Source: NFIRS 5.0.

Confined fires

The NFIRS allows abbreviated reporting for confined fires, and many reporting details of these fires are not required, 

nor are they reported. (Not all fires limited to the object of origin are counted as confined fires.13) For example, a fire 

contained to a chair or clothes dryer is not defined as a confined fire in the NFIRS because of the greater potential 

for spread. Unlike fires in pots or chimneys, there is no container to stop the fire, even though the fire did not spread 

beyond the object of origin.

Because 71% of multifamily fires are confined, the profiles of when multifamily confined fires occurred and their 

causes dominated the overall multifamily fire profile. As shown in Table 1, confined cooking fires accounted for 63% 

of multifamily fire incidents and dominated the cause of multifamily fires.
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The occurrence of confined multifamily fires was greatest during the hours from 5 to 8 p.m., when they accounted 

for 77% of all multifamily fires that occurred during this period. Moreover, confined cooking fires accounted for 91% 

of the confined fires and 70% of all fires in multifamily buildings that occurred during this time period.

Confined multifamily fires also peaked in January and declined throughout the spring, reaching the lowest incidence 

during the month of July.

Nonconfined fires

The next sections of this topical report address nonconfined residential fires — the larger and more serious fires — 

where more detailed fire data are available, as they are required to be reported in the NFIRS.

Causes of nonconfined multifamily residential building fires

While cooking was the leading cause for multifamily fires overall (74%), it only accounted for 15% of all nonconfined 

multifamily fires (Figure 4). The next leading causes were other unintentional, careless actions (14%); electrical 

malfunctions (10%); open flames, such as candles or matches (9%); other heat sources (8%); and appliances (8%). 

These 5 causes accounted for 50% of the fires.14

Figure 4. Causes of nonconfined multifamily residential building fires (2017-2019) Causes

Percent of nonconfined multifamily residential building fires

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Unknown

Cause under investigation

Other unintentional, careless

Equipment misoperation, failure

Exposure

Natural

Other equipment

Other heat

Open flame

Appliances

Electrical malfunction

Cooking

Heating

Smoking

Playing with heat source

Intentional

Percent of nonconfined multifamily 

residential building fires with cause

determined

Percent of all nonconfined multifamily

residential building fires

7.1

5.4

0.8

0.6

7.4

5.6

4.7

14.5

11.0

10.0

7.6

8.4

6.3

9.1

6.9

8.4

6.3

1.1

0.8

1.4

1.1

4.1

3.1

6.6

5.0

13.8

10.4

2.5

1.9

24.5

3.6

Source: NFIRS 5.0.

Notes:	 1.	Causes are listed in order of the USFA Structure Fire Cause Hierarchy for ease of comparison of fire causes across different aspects of the fire problem. Fires

are assigned to 1 of 16 cause groupings using a hierarchy of definitions, as shown in this figure. A fire is included in the highest category into which it fits. If it

does not fit the top category, then the second one is considered, and if not that one, the third, and so on. For example, if the fire is judged to be intentionally

set and a match was used to ignite it, it is classified as intentional and not open flame because intentional is higher in the hierarchy.

2. Total percentages do not add up to 100% due to rounding.
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Where nonconfined multifamily residential building fires start (area of fire origin)

Nonconfined multifamily fires most often started in cooking areas and kitchens (33%), as shown in Table 4. The next 

leading area of fire origin was bedrooms (13%). Additional fires started in family rooms or living rooms (6%), exterior 

balconies or unenclosed porches (6%), bathrooms (5%), and laundry areas (5%). These areas of origin do not include 

areas associated with confined fires, as that information generally is not reported for confined fires. Cooking fires 

were a substantial percentage of all multifamily fires. Therefore, it is likely that the kitchen was the leading area of 

fire origin for all multifamily fires.

Nonetheless, nonconfined multifamily fires that started in the kitchen were not exclusively cooking fires — only 40% 

of fires that started in the kitchen were cooking fires. Other unintentional, careless actions (18%) and equipment 

misoperation or failure (12%) accounted for another 30% of these kitchen fires. Additional nonconfined multifamily 

fires that started in the kitchen were caused by other heat sources (9%) and appliances (6%).

Table 4. Leading areas of fire origin in nonconfined multifamily residential building fires (2017-2019)

Areas of fire origin Percent

(unknowns apportioned)

Cooking area, kitchen 33.4

Bedrooms 12.6

Common room, den, family room, living room, lounge 6.2

Exterior balcony, unenclosed porch 5.8

Bathrooms 4.8

Laundry area 4.8

Source: NFIRS 5.0.

How nonconfined multifamily residential building fires start (heat source)

Figure 5 shows sources of heat categories in nonconfined multifamily fires. The heat from powered equipment 

category accounted for 52% of nonconfined multifamily fires. This category includes radiated or conducted heat from 

operating equipment (19%), heat from other powered equipment (17%), and electrical arcing (11%).

Heat from open flame or smoking materials accounted for 20% of nonconfined multifamily fires. This category 

includes cigarettes (7%), heat from miscellaneous open flames or smoking materials (4%), lighters and matches 

(combined, 4%), and candles (4%). The third largest heat source category pertains to hot or smoldering objects (14%). 

This category includes miscellaneous hot or smoldering objects (7%) and hot embers or ashes (5%).
TFRS Volume 21, Issue 7 | Multifamily Residential Building Fires (2017-2019)

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Figure 5. Sources of heat in nonconfined multifamily residential building fires by major category (2017-2019)

Percent of nonconfined multifamily residential building fires

Heat source

0.0 10.0 20.0 30.0 40.0 50.0 60.0

Undetermined

Multiple heat sources including

 multiple ignitions

Explosives, fireworks

Chemical, natural heat source

Other heat source

Heat spread from another fire

Hot or smoldering objects

Heat from open flame or

 smoking material

Heat from powered equipment

31.1

0.3

0.4

0.5

0.7

0.9

1.3

3.9

5.6

4.2

6.1

9.3

13.5

14.0

20.3

35.9

52.1

Percent of all nonconfined multifamily

residential building fires

Percent of nonconfined multifamily 

residential building fires with heat 

source determined

Source: NFIRS 5.0.

Note:	 Total percentage of all nonconfined multifamily residential building fires does not add up to 100% due to rounding.

Fire spread in nonconfined multifamily fires

Figure 6 shows the extent of fire spread in nonconfined multifamily fires. The majority of nonconfined fires, 69%, 

were limited to the object or room of fire origin. In 51% of nonconfined fires, the fire was limited to the room of origin; 

in another 18% of fires, the fire was limited to the object of origin. In 31% of nonconfined multifamily fires, the fire 

extended beyond the room of origin. The leading causes of these larger fires were unintentional, careless actions 

(14%); exposures (13%); electrical malfunctions (11%); open flames (10%); smoking (9%); and intentional actions (9%). 

In contrast, 54% of all other nonconfined residential building fires (excluding multifamily building) extended beyond 

the room of origin. AESs, such as sprinklers, can aid in containing multifamily fires, as discussed in a later section.

Figure 6. Extent of fire spread in nonconfined multifamily residential building fires (2017-2019)

8.3

Fire spread

Percent of nonconfined multifamily residential building fires

0.0 10.0 20.0 30.0 40.0 50.0 60.0

Beyond building of origin

Limited to building of origin

Limited to floor of origin

Limited to room of origin

Limited to object of origin 18.2

50.6

10.3

18.6

2.2

Source: NFIRS 5.0.

Note: Total does not add up to 100% due to rounding.
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Factors contributing to ignition in nonconfined multifamily residential building fires

Table 5 shows the categories of factors contributing to ignition for nonconfined multifamily fires. By far, the leading 

category contributing to the ignition of nonconfined multifamily fires was the misuse of material or product (45%). 

Abandoned or discarded materials (16%) and a heat source too close to combustible materials (15%) were the leading 

specific factors contributing to ignition in this category.

Operational deficiency, the second leading category, contributed to 21% of nonconfined multifamily fires. Unattended 

equipment was the leading factor in the operational deficiency category, and it accounted for 12% of all nonconfined 

multifamily fires. Electrical failures and malfunctions was the third leading category of factors contributing to ignition 

at 16%.

Table 5. Factors contributing to ignition for nonconfined multifamily residential building fires by major 

category (where factors contributing to ignition were specified, 2017-2019)

Factors contributing to ignition category Percent of nonconfined multifamily residential 

building fires (unknowns apportioned)

Misuse of material or product 45.3

Operational deficiency 21.1

Electrical failure, malfunction 15.9

Fire spread or control 7.3

Mechanical failure, malfunction 6.2

Other factors contributing to ignition 6.2

Natural condition 1.5

Design, manufacture, installation deficiency 0.8

Source: NFIRS 5.0.

Notes:	 1.	Includes only incidents where factors that contributed to the ignition of the fire were specified.

	 2.	Multiple factors contributing to fire ignition may be noted for each incident; the total will exceed 100%.

Alerting/suppression systems in multifamily residential building fires

Fire fatalities and injuries have declined over the last 40 years, partly due to new technologies to detect and extinguish 

fires. In addition, residential sprinklers have gained support from the fire service and many residential communities.

Smoke alarm data are available for both confined and nonconfined fires, although for confined fires, the data are 

very limited in scope. Since different levels of data are reported on smoke alarms in confined and nonconfined fires, 

the analyses are performed separately. The data presented in Tables 6 through 8 show the raw counts from the 

NFIRS dataset and are not scaled to national estimates of smoke alarms in multifamily fires. In addition, the NFIRS 

does not allow for the determination of the type of smoke alarm — that is, if the smoke alarm was photoelectric or 

ionization — or the location of the smoke alarm with respect to the area of fire origin.

Smoke alarms in nonconfined fires

Because of various avenues of fire notification in multifamily buildings, the detailed smoke alarm analyses in the next 

section focus on all nonconfined fires in multifamily buildings.15

Smoke alarms were reported as present in 64% of nonconfined multifamily fires. In 18% of nonconfined multifamily 

fires, no smoke alarms were present. In another 18% of these fires, firefighters were unable to determine if a smoke 

alarm was present (Table 6).
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When operational status is considered, the percentage of smoke alarms reported as present (64%) consisted of:

ĵ Present and operated — 42%.

ĵ Present, but did not operate — 14% (fire too small, 8%; alarm failed to operate, 6%).

ĵ Present, but operational status unknown — 9%.16

When only the subset of incidents where smoke alarms were reported as present was analyzed, smoke alarms 

were reported to have operated in 64% of these incidents. The alarms failed to operate in 9% of the incidents, and 

the fire was too small to activate the alarm in another 12%. Additionally, the operational status of the alarm was 

undetermined in 15% of these incidents.

At least 18% of nonconfined fires in multifamily buildings had no smoke alarms present — and perhaps more if fires 

without information on smoke alarms were also considered.17 A large proportion of reported fires without smoke 

alarms may reflect the effectiveness of the alarms themselves; smoke alarms do not prevent fires, but they may 

prevent a fire from being reported if it is detected at an early stage and extinguished before the fire department 

becomes involved. Alternatively, fires in homes without smoke alarms may not be detected at an early stage, causing 

them to grow large, require fire department intervention, and thus be reported.18

Properly installed and maintained smoke alarms provide an early warning signal to everyone in a home if a fire 

occurs. Smoke alarms help save lives and property. The USFA continues to partner with other government agencies, 

non-government organizations, and fire service organizations to improve and develop new smoke alarm technologies. 

More information on smoke alarm technologies, performance, training bulletins, and public education and outreach 

materials can be found at http://www.usfa.fema.gov/prevention/technology/smoke_fire_alarms.html. Additionally, the 

USFA’s position statement on home smoke alarms is available at https://www.usfa.fema.gov/about/smoke_alarms_

position.html.

Table 6. NFIRS smoke alarm data for nonconfined multifamily residential building fires (2017-2019)

Presence of 

smoke alarms Smoke alarm operational status Smoke alarm effectiveness Count Percent

 Present 

Fire too small to activate smoke alarm 5,133 8.0

Smoke alarm operated

Smoke alarm alerted occupants; 

occupants responded 20,118 31.2

Smoke alarm alerted occupants; 

occupants failed to respond 1,135 1.8

No occupants 2,626 4.1

Smoke alarm failed to alert occupants 378 0.6

Undetermined 2,477 3.8

Smoke alarm failed to operate 3,569 5.5

Undetermined 6,046 9.4

None present 11,469 17.8

Undetermined 11,430 17.8

Total reported 

incidents 64,381 100.0

Source: NFIRS 5.0.

Note:	 The data presented in this table are raw data counts from the NFIRS dataset summed (not averaged) from 2017 to 2019. They do not represent national estimates

of smoke alarms in nonconfined fires in multifamily residential buildings. They are presented for informational purposes.
TFRS Volume 21, Issue 7 | Multifamily Residential Building Fires (2017-2019)

11

Smoke alarms in confined fires

Less information about smoke alarm status is collected for confined fires, but the data still give important insights 

about the effectiveness of alerting occupants in these types of fires. Smoke alarms operated and alerted occupants 

in 53% of confined multifamily fires (Table 7). In 13% of confined multifamily fires, the occupants were not alerted by 

the smoke alarm.19 In 34% of the confined fires, the smoke alarm effectiveness was unknown.

Table 7. NFIRS smoke alarm data for confined multifamily residential building fires (2017-2019)

Smoke alarm effectiveness Count Percent

Smoke alarm alerted occupants 84,920 53.2

Smoke alarm did not alert occupants 20,170 12.6

Unknown 54,569 34.2

Total reported incidents 159,659 100.0

Source: NFIRS 5.0.

Note:	 The data presented in this table are raw data counts from the NFIRS dataset summed (not averaged) from 2017 to 2019. They do not represent national estimates

of smoke alarms in confined multifamily residential building fires. They are presented for informational purposes.

Automatic extinguishing systems in nonconfined multifamily residential building fires

AES data are available for both confined and nonconfined fires, although for confined fires, the data are also very 

limited in scope. In confined multifamily residential building fires, an AES was present in 1% of reported incidents.20

Full or partial AESs were present in 15% of nonconfined multifamily fires (Table 8). The presence of suppression 

systems (most likely sprinkler systems) was greater in nonconfined multifamily fires than in nonconfined fires in all 

other residential buildings (2%), possibly because of code requirements.

Residential sprinkler systems help to reduce the risk of deaths and injuries, homeowners insurance premiums, and 

uninsured property losses. Despite these advantages, many homes do not have AESs, although they are often found 

in hotels and businesses. Sprinklers are required by code in hotels and many multifamily residences. There are major 

movements in the U.S. fire service to require sprinklers in all new homes. Unfortunately, at present, they are largely 

absent in residences nationwide.21

The USFA and fire service officials across the nation are working to promote and advance residential fire sprinklers. 

More information on costs and benefits, performance, training bulletins, and public education and outreach materials 

regarding residential sprinklers is available at http://www.usfa.fema.gov/prevention/technology/home_fire_sprinklers.

html. Additionally, the USFA’s position statement on residential sprinklers is available at http://www.usfa.fema.gov/

about/sprinklers_position.html.

Table 8. NFIRS automatic extinguishing system data for nonconfined multifamily residential building fires 

(2017-2019)

Automatic extinguishing system presence Count Percent

Automatic extinguishing system present 9,173 14.2

Partial system present 425 0.7

Automatic extinguishing system not present 50,786 78.9

Unknown 3,997 6.2

Total reported incidents 64,381 100.0

Source: NFIRS 5.0.

Note:	 The data presented in this table are raw data counts from the NFIRS dataset summed (not averaged) from 2017 to 2019. They do not represent national estimates

of AESs in nonconfined fires in multifamily residential buildings. They are presented for informational purposes.
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Examples

The following are recent examples of multifamily fires reported by the media:

ĵ June 2021: A second-floor apartment was gutted, and neighboring apartments were damaged, in a 2-alarm, 

midafternoon fire in downtown Hanover, Pennsylvania. The fire started in the bedroom, spreading throughout 

the unit and extending through the ceiling. The resident of the apartment, who was sleeping when the fire started, 

woke to find smoke and fire around him. That resident, as well as others in the building, were able to escape 

without injury. Although firefighters extinguished the fire in about 15 minutes, 7 apartments sustained damage 

and approximately 15 residents were displaced. The cause of the fire was under investigation.22

ĵ June 2021: A midday townhouse fire in West Springfield, Virginia, started when cooking oil ignited after it was 

left unattended in a pot on the kitchen stove. Upon arrival, firefighters located and rapidly extinguished the fire. 

Damages were estimated at $62,500 and 6 occupants were displaced. Working smoke alarms were present in 

the home, and there were no reported civilian or firefighter injuries.23

ĵ February 2021: A Lafayette, Louisiana, condominium sustained heavy fire damage to the attic and roof areas when 

a central heating system malfunctioned and ignited. The owner of the condo smelled smoke and discovered the 

late-night fire in the attic after checking the access door. Upon arrival, firefighters found smoke and flames coming 

from the roof and spent 3 hours battling the blaze. The interior of the home sustained water damage from the fire 

suppression efforts. In addition, a neighboring condo sustained light water damage. No injuries were reported.24

NFIRS data specifications for multifamily residential building fires

Data for this report were extracted from the NFIRS annual Public Data Release files for 2017, 2018 and 2019. Only 

Version 5.0 data were extracted.

Multifamily residential building fires were defined using the following criteria:

ĵ Incidents with Aid Types 3 (mutual aid given) and 4 (automatic aid given) were excluded to avoid counting a single 

incident more than once.

ĵ Incident Types 111 to 123 (excluding Incident Type 112):

Incident 

Type Description

111 Building fire

113 Cooking fire, confined to container

114 Chimney or flue fire, confined to chimney or flue

115 Incinerator overload or malfunction, fire confined

116 Fuel burner/boiler malfunction, fire confined

117 Commercial compactor fire, confined to rubbish

118 Trash or rubbish fire, contained

120 Fire in mobile property used as a fixed structure, other

121 Fire in mobile home used as fixed residence

122 Fire in motor home, camper, recreational vehicle

123 Fire in portable building, fixed location

Note: Incident Types 113 to 118 do not specify if the structure is a building.
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ĵ Property Use 429:

Property 

Use Description

429 Multifamily dwelling. Includes apartments, condos, town houses, row houses, tenements.

ĵ Structure Type:

Ý For Incident Types 113 to 118:

f 1 — Enclosed building, or

f 2 — Fixed portable or mobile structure, or

f Structure Type not specified (null entry).

Ý For Incident Types 111 and 120 to 123:

f 1 — Enclosed building, or

f 2 — Fixed portable or mobile structure.

Although voluntary, the NFIRS is the world’s largest national, annual database of fire incident information. By 

contributing to the NFIRS, the fire service is helping in making data-based decisions from local budget development 

to the identification of national preparedness initiatives. It is important that fire departments participate in the NFIRS 

and critical that the data they report is complete and accurate so that sound decisions can be made.

The analyses contained in this report reflect the current methodologies used by the USFA. The USFA is committed 

to providing the best and most current information on the U.S. fire problem and continually examines its data and 

methodology to fulfill this goal. Because of this commitment, data collection strategies and methodological changes 

are possible and do occur. As a result, analyses and estimates of the fire problem may change slightly over time. 

Previous analyses and estimates on specific issues (or similar issues) may have used different methodologies or data 

definitions and may not be directly comparable to the current ones. 

Information regarding the USFA’s national estimates for residential building fires, as well as the data sources used to 

derive the estimates, can be found in the document “Data Sources and National Estimates Methodology Overview 

for the U.S. Fire Administration’s Topical Fire Report Series (Volume 21),” https://www.usfa.fema.gov/downloads/pdf/

statistics/data-sources-and-national-estimates-methodology-vol21.pdf. This document also addresses the specific 

NFIRS data elements analyzed in the topical reports, as well as “unknown” data entries and missing data.

To request additional information, visit: http://www.usfa.fema.gov/contact.html. Provide feedback on this report.

Notes:

1

National estimates are based on 2017 to 2019 native Version 5.0 data from the NFIRS, residential structure fire loss estimates from the 

National Fire Protection Association’s (NFPA’s) annual surveys of fire loss, and the USFA’s residential building fire loss estimates: http://www.

usfa.fema.gov/data/statistics/order_download_data.html. Further information on the USFA’s residential building fire loss estimates can be 

found in the “National Estimates Methodology for Building Fires and Losses,” August 2012, http://www.usfa.fema.gov/downloads/pdf/statistics/

national_estimate_methodology.pdf. For detailed information regarding the NFPA’s survey methodology, see the NFPA’s “Methodology used in 

calculating national estimates from the NFPA’s fire experience survey,” August 2020, https://www.nfpa.org/-/media/Files/News-and-Research/

Fire-statistics-and-reports/US-Fire-Problem/Methodsfirelossandothers.ashx. In this topical report, fires are rounded to the nearest 100, deaths 

to the nearest 5, injuries to the nearest 25 and dollar loss to the nearest $100 million.

2In NFIRS Version 5.0, a structure is a constructed item of which a building is one type. In previous versions of the NFIRS, the term “residential 

structure” commonly referred to buildings where people live. To coincide with this concept, the definition of a residential structure fire for the 

NFIRS 5.0 includes only those fires where the NFIRS 5.0 Structure Type is 1 or 2 (enclosed building and fixed portable or mobile structure) with 

a residential property use. Such structures are referred to as “residential buildings” to distinguish these buildings from other structures on 

residential properties that may include fences, sheds and other uninhabitable structures. In addition, confined fire incidents that have a residential 

property use, but do not have a structure type specified, are presumed to occur in buildings. Nonconfined fire incidents that have a residential 

property use without a structure type specified are considered to be invalid incidents (structure type is a required field) and are not included.

3USFA, Topical Fire Report Series, “Residential Building Fires (2017-2019),” Volume 21, Issue 2, May 2021, https://www.usfa.fema.gov/downloads/

pdf/statistics/v21i2.pdf. 4“One- and two-family residential buildings” include detached dwellings, manufactured homes, mobile homes not in transit, and duplexes.
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5Fire department participation in the NFIRS is voluntary; however, some states do require their departments to participate in the state system. 

Additionally, if a fire department is a recipient of a Fire Act Grant, participation is required. From 2017 to 2019, 68% of the NFPA’s annual average 

estimated 1,309,800 fires to which fire departments responded were captured in the NFIRS. Thus, the NFIRS is not representative of all fire 

incidents in the U.S. and is not a “complete” census of fire incidents. Although the NFIRS does not represent 100% of the incidents reported to 

fire departments each year, the enormous dataset exhibits stability from one year to the next without radical changes. Results based on the 

full dataset are generally similar to those based on part of the data.

6In the NFIRS, confined fires are defined by Incident Type Codes 113 to 118.

7The NFIRS distinguishes between “content” and “property” loss. Content loss includes losses to the contents of a structure due to damage by 

fire, smoke, water and overhaul. Property loss includes losses to the structure itself or to the property itself. Total loss is the sum of the content 

loss and the property loss. For confined fires, the expectation is that the fire did not spread beyond the container (or rubbish for Incident Type 

code 118), and hence, there was no property damage (damage to the structure itself) from the flames. However, there could be property damage 

as a result of smoke, water and overhaul.

8The average fire death and fire injury loss rates computed from the national estimates do not agree with average fire death and fire injury loss 

rates computed from the NFIRS data alone. The fire death rate computed from national estimates is 1,000 x (400/106,700) = 3.7 deaths per 1,000 

multifamily residential building fires, and the fire injury rate is 1,000 x (3,875/106,700) = 36.3 injuries per 1,000 multifamily residential building fires.

9For this report, the time of the fire alarm is used as an approximation for the general time at which the fire started. However, in the NFIRS, it is 

the time at which the fire was reported to the fire department.

10The USFA Structure Fire Cause Methodology was used to determine the cause of residential building fires. The cause methodology and 

definitions can be found in the document “National Fire Incident Reporting System Version 5.0 Fire Data Analysis Guidelines and Issues,” July 

2011, https://www.usfa.fema.gov/downloads/pdf/nfirs/nfirs_data_analysis_guidelines_issues.pdf. 11Fires caused by intentional actions include, but are not limited to, fires that are deemed to be arson. Intentional fires are those fires that are 

deliberately set and include fires that result from the deliberate misuse of a heat source and fires of an incendiary nature (arson) that require fire 

service intervention. For information and statistics on arson fires only, refer to the Uniform Crime Reporting Program arson statistics from the 

U.S. Department of Justice, FBI, Criminal Justice Information Services Division, https://www.fbi.gov/about-us/cjis/ucr/ucr (accessed June 14, 2021). 12The American Housing Survey does not indicate the number of fireplaces, chimneys and fireplace-related equipment; however, it does collect 

data on fireplaces, etc., as the primary heating unit, which applies to this analysis. U.S. Department of Housing and Urban Development (HUD) 

and U.S. Census Bureau, 2019 American Housing Survey – Table Creator, select “2019 (Year) National (Area) Housing Unit Characteristics (Table); 

Units by Structure Type (Variable 1),” https://www.census.gov/programs-surveys/ahs/data/interactive/ahstablecreator.html?s_areas=00000&s_

year=2019&s_tablename=TABLE0&s_bygroup1=3&s_bygroup2=1&s_filtergroup1=1&s_filtergroup2=1 (accessed June 15, 2021). 13As noted previously, confined building fires are small fire incidents that are limited in scope, are confined to noncombustible containers, rarely 

result in serious injury or large content loss, and are expected to have no significant accompanying property loss due to flame damage. In the 

NFIRS, confined fires are defined by Incident Type Codes 113 to 118.

14Total does not add up to 50% due to rounding.

15The discussion in the “Smoke Alarms in Nonconfined Fires” section of this report includes nonconfined fires that occurred in both occupied

and unoccupied multifamily residential buildings. There are 2 principal reasons for including both states of occupancy in the analysis. First, 

requirements that smoke alarms be interconnected in multifamily units are being included in an increasing number of local building codes. As 

a result, interconnected alarms may be present in more recently constructed multifamily residential buildings in many jurisdictions. Second, in 

all multifamily residential buildings, the proximity or closeness of the dwelling units to one another heightens the possibility that an occupant 

would hear an alarm, smell smoke or see flames coming from a neighboring unit. Thus, even though a fire may start in an unoccupied unit, it 

is possible that a fire department will be notified either automatically or by an occupant in a neighboring unit, who may become alerted to the 

presence of a fire either by the sounding of an interconnected alarm or by other physical cues.

16Total does not add up to 64% due to rounding.

17Here, at least 18% of nonconfined fires in multifamily residential buildings had no smoke alarms present — the 18% that were known to not 

have smoke alarms and some portion (or as many as all) of the fires where the smoke alarm presence was undetermined.

18Greene, Michael and Andres, Craig, “2004-2005 National Sample Survey of Unreported Residential Fires,” Division of Hazard Analysis, Directorate 

for Epidemiology, U.S. Consumer Product Safety Commission, July 2009. The “2004-2005 National Sample Survey of Unreported Residential Fires,” 

however, suggests that this may not be the case. It is observed that “if this conjecture is true, it would suggest that the percentage decrease in 

fire department-attended fires would have been greater than unattended fires in the 20-year period between the surveys.”

19In confined fires, the entry “smoke alarm did not alert occupants” can mean no smoke alarm was present; the smoke alarm was present but 

did not operate; the smoke alarm was present and operated, but the occupant(s) was already aware of the fire; or there were no occupants 

present at the time of the fire.

20As confined fire codes are designed to capture fires contained to noncombustible containers, it is not recommended to code a fire incident as 

a small-, low- or no-loss confined fire incident if the AES operated and contained the fire as a result. The preferred method is to code the fire as 

a standard fire incident with fire spread confined to the object of origin and provide the relevant information on AES presence and operation.

21HUD and U.S. Census Bureau, American Housing Survey for the United States: 2011, September 2013, “Health and Safety Characteristics-All Occupied 

Units (National),” Table S-01-AO, https://www.census.gov/content/dam/Census/library/publications/2013/demo/h150-11.pdf (accessed June 14, 2021). 22Jones, Harrison, “2-alarm fire displaces more than a dozen residents in downtown Hanover apartment building,” www.eveningsun.com, 

June 14, 2021, https://www.eveningsun.com/story/news/2021/06/14/15-displaced-7-apartments-damaged-hanover-borough-fire/7682074002/

(accessed June 15, 2021).

23Fairfax County Fire and Rescue Department, “Unattended Cooking Cause of West Springfield Townhouse Fire,” ffxfirerescue.wordpress.com, June 

10, 2021, https://ffxfirerescue.wordpress.com/2021/06/10/unattended-cooking-cause-of-west-springfield-townhouse-fire/ (accessed June 15, 2021). 24Gagliano, Katie, “Heating system malfunction causes fire and heavy damage to Lafayette condo,” www.theadvocate.com, Feb. 17, 2021, https://

www.theadvocate.com/acadiana/news/crime_police/article_8fe9bc2e-716f-11eb-bbad-9720ac1a35e4.html (accessed June 15, 2021).