U.S. Department of Homeland Security • U.S. Fire Administration

National Fire Data Center • Emmitsburg, Maryland 21727

www.usfa.dhs.gov/statistics/reports/index.shtm

Topical Fire Report Series Volume 9, Issue 8 / December 2009

Intentionally Set Fires in Residential Buildings

These short 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 fire-related 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

■ An estimated 18,100 intentionally set residential building fires occur annually in the United 

States. These fires result in approximately 290 deaths, 850 injuries, and $533 million in 

property loss each year.

■ Approximately 5 percent of residential building fires are intentionally set.

■ Lighters (23 percent) and matches (19 percent) are the leading heat sources of intentionally 

set fires in residential buildings.

■ Seventy-four percent of intentionally set fires in residential buildings occur in one- or twofamily dwellings. Nineteen percent of fires occur in multifamily dwellings. 

■ Rubbish, trash, and waste (8 percent), magazines, newspapers, and writing paper (7 

percent), and flammable liquids or gas, uncontained (7 percent) are the items most often 

first ignited in intentionally set fires in residential buildings. 

From 2004 to 2006, an estimated average of 18,100 

intentionally set fires in residential buildings occurred 

each year in the United States. Intentionally set fires 

account for 5 percent of residential building fires responded 

to by fire departments across the Nation.1,2,3 These fires 

resulted in an average of approximately 290 deaths, 850 

injuries, and $533 million in property loss each year. 

As part of the Intentionally Set Fires Topical Reports series, 

this topical report addresses the characteristics of intentionally set fires in residential buildings reported to the National 

Fire Incident Reporting System (NFIRS) between 2004 

and 2006. Intentional fires are those fires that require fire 

service intervention and are deliberately set. These fires 

include fires that result from deliberate misuse of a heat 

source, fires of an incendiary nature (arson), as well as other 

deliberate acts. The first report, Intentionally Set Fires (Volume 

9, Issue 5), presents the overall intentionally set fires problem. Other aspects of the intentionally set fire problem are 

explored in Intentionally Set Outdoor Fires (Volume 9, Issue 6) 

and Intentionally Set Vehicle Fires (Volume 9, Issue 7).

Table 1 presents losses, averaged over this 3-year period, of 

all reported residential building fires and intentionally set 

fires in residential buildings.4

Table 1. Loss Measures for Intentionally Set 

Fires in Residential Buildings 

(3-year average, 2004–2006)

Measure Residential 

Building Fires

Intentionally Set 

Residential Building 

Fires

Average Loss: N/A N/A

Fatalities/1,000 Fires 5.5 8.5

Injuries/1,000 Fires 28.5 37.9

Dollar Loss/Fire $12,304 $17,819

Source: NFIRS 5.0 

Note: Average loss for fatalities and injuries is computed per 1,000 fires; average dollar loss is computed per fire.

Where Intentionally Set Fires in 

Residential Buildings Occur

Approximately three-quarters of intentionally set fires in 

residential buildings occurred in one- and two-family 

residential properties. Multifamily and other residential 

properties accounted for 19 and 7 percent, respectively 

(Table 2). Other residential properties included barracks, 

dormitories, and boarding/rooming houses among other 

categories.

continued on next page
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 2

Table 2. Intentionally Set Fires in Residential Buildings by Type of Residential Property 

and Type of Incident (2004–2006)

Residential Property Type

Incident Type

Residential Total

Building Fire

Confined Residential 

Building Fire

Fire in Mobile 

Property Used as a 

Building

Other Residential 

Building Fire

One- and two-family 61.8 6.7 4.3 1.6 74.4

Multifamily 16.9 1.7 0.0 0.4 19.0

Other residential property 5.1 0.8 0.5 0.2 6.6

Total 83.7 9.3 4.9 2.1 100.0

Source: NFIRS 5.0 

Note: Totals may not add to 100 percent due to rounding.

Eighty-four percent of intentionally set fires in residential buildings occurred in typical residential buildings. 

Confined fires, small fire incidents that are limited in scope, 

accounted for 9 percent of intentionally set fires (with trash 

or rubbish fires accounting for 59 percent of these confined 

fires).5

 Five percent of intentionally set fires occurred in 

mobile properties used as buildings, with mobile homes 

used as fixed residences as the leading category. Only 2 percent of intentionally set fires occurred in other residential 

buildings (Table 2). 

When Intentionally Set Fires in 

Residential Buildings Occur

As shown in Figure 1, intentionally set fires in residential 

buildings occurred mainly in the evening hours, peaking 

from 8 p.m. to 10 p.m., and then declining throughout the 

night and early morning reaching the lowest point during 

the morning hours (6 a.m. to 9 a.m.). The 2-hour evening 

period accounts for 11 percent of these intentionally set 

fires and the 3-hour morning period accounts for 

7 percent.6

Figure 1. Intentionally Set Fires in Residential Buildings by Time of Alarm (2004–2006) Percent of Fires

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

Mid-1AM

 1AM-2AM

 2AM-3AM

 3AM-4AM

 4AM-5AM

 5AM-6AM

 6AM-7AM

 7AM-8AM

 8AM-9AM

 9AM-10AM

 10AM-11AM

 11AM-12PM

 12PM-1PM

 1PM-2PM

 2PM-3PM

 3PM-4PM

 4PM-5PM

 5PM-6PM

 6PM-7PM

 7PM-8PM

 8PM-9PM

 9PM-10PM

10PM-11PM

11PM-Mid

5.0 5.0 4.7

5.4

5.1

5.6 5.6

4.4

4.8

5.3 5.3

4.5

4.0 3.7

3.0

3.4 3.3

2.8

4.0 3.9 4.2

2.1 2.4 2.4

Source: NFIRS 5.0 

Figure 2 illustrates that the percentage of intentionally set 

fires in residential buildings ranges from 7 to 9 percent 

for each month throughout the year, peaking slightly in 

July, but not by much more than the previous and following months. From March to August, fires fluctuate 

between 8 and 9 percent, accounting for just over half of all 

intentionally set fires in residential buildings (53 percent). 

While fireworks do play a role in the July fires, their role is 

limited to July 4 and the days following (July 4 – July 6) 

when fireworks account for 16 percent of intentionally set 

residential building fires. 
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 3

Figure 2. Intentionally Set Fires in Residential Buildings by Month (2004–2006)

January

February

March

April

May

Se

N

June

July

August

ptember

October

ovember

December

Percent of Fires

10.0

9.0

8.0

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

7.8 7.4

8.7 8.6 8.8

7.8

8.5

7.8

8.6

9.4

7.7 

8.9

 

 

 

 

 

 

 

 

Source: NFIRS 5.0 

Where Intentionally Set Residential 

Building Fires Start (Area of Fire Origin)

Thirty-eight percent of intentionally set fires in residential 

buildings occurred in “function areas” of a house such as 

bedrooms and kitchens; of intentionally set fires in residential buildings, 19 percent occur in bedrooms and 9 

percent occur in cooking areas and kitchens. The second 

leading area of fire origin category for intentionally set fires 

in residential buildings is structural areas—walls, ceilings, 

floors, attics, crawl spaces—at 16 percent. The third most 

common area of fire origin in intentionally set fires in 

residential buildings occurred in other areas (13 percent) 

which include hallways, stairways, and entranceways. An 

additional 9 percent occur in common rooms, dens, family 

rooms, living rooms, and lounges (referred to as assembly 

areas) (Figure 3).

Figure 3. Area of Fire Origin in Intentionally Set Fires in Residential Buildings (2004–2006)

Function areas

Structural area

Other area of fire origin

Assembly or sales area

Outside area

Storage area

Multiple areas

Equipment or service area

Vehicle area

Service facilities

Technical processing areas

Undetermined

Percent of Fires

 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 

9.4

8.8

13.3

12.5

15.5

14.5

38.3

35.9

8.6

8.1

7.0

4.8

0.9

0.9

0.7

0.7

0.6

0.0

0.0

6.3

0.6

5.1

Percent of intentional residential 

fires with area of fire origin 

determined

Percent of all intentional 

residential fires

7.5

Source: NFIRS 5.0 
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 4

How Intentionally Set Residential Building 

Fires Start (Heat Source)

Sixty-four percent of intentionally set fires in residential 

buildings derive their heat source from open flame or 

smoking materials (Figure 4). Not surprisingly, the subcomponents of this category comprise three of the top four 

leading sources of heat in all residential building intentionally set fires—lighters for cigarettes or cigars (23 percent), 

matches (19 percent), and heat from other open flame or 

smoking materials (15 percent). 

Another 9 percent of intentionally set fires in residences 

derive their heat source from powered equipment and 8 

percent are from explosives or fireworks. 

Figure 4. Sources of Heat in Intentionally Set Fires in Residential Buildings (2004–2006)

Heat from open flame or smoking materials

Heat from powered equipment

Explosive, fireworks

Other heat source

Hot or smoldering object

Multiple heat sources including multiple ignitions

Heat spread from another fire

Chemical, natural heat source

Undetermined

Percent of Fires

 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0

64.4

41.7

8.8

5.7

5.2

4.4

6.5

4.2

4.8

3.1

0.2

0.4

0.2

35.2

0.4

6.7

Percent of intentional residential fires 

with heat source determined

Percent of all intentional residential 

fires

8.1

Source: NFIRS 5.0 

What Ignites First in Intentionally Set 

Residential Building Fires

Twenty-one percent of the items first ignited in intentionally set fires in residential buildings fall under the structural 

component or finish category (Figure 5). This category 

includes materials such as floor coverings, rugs, carpets, 

or mats as well as exterior sidewall coverings, surfaces, or 

finishes. The second leading category, soft goods and wearing apparel, accounted for 20 percent of intentional fires in 

residential buildings and third was general materials (17 

percent). 

Rubbish, trash, and waste (8 percent); magazines, newspapers, and writing paper (7 percent); and flammable liquids 

or gas, uncontained (7 percent) are the specific items most 

often first ignited in intentionally set fires in residential 

buildings.
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 5

Figure 5. Item First Ignited in Intentionally Set Fires in Residential Buildings (2004–2006) 

Structural component or finish

Soft goods, wearing apparel

General materials

Liquids, piping, filters

Furniture, utensils

Organic materials

Multiple items first ignited

Other item first ignited

Storage supplies

Adornment, recreational material, signs

Undetermined

Percent of Fires

 0.0 5.0 10.0 15.0 20.0 25.0 30.0

17.4

13.3

11.1

8.5

6.8

4.7

5.5

4.2

5.3

4.1

2.3

1.8

1.3

23.7

3.0

6.2

Percent of intentional residential fires 

with item first ignited determined

Percent of all intentional

residential fires

8.9

21.2

16.2

19.5

14.9

Source: NFIRS 5.0 

Fire Spread

Figure 6 shows the fire spread in intentionally set fires in 

residential buildings. In 34 percent of the intentional fires, 

the fire was confined to the object of origin. Thirty percent 

of intentionally set fires in residential buildings were confined to the building, and an additional 23 percent were 

confined to the room of origin.

Figure 6. Extent of Fire Spread in Intentionally Set Fires in Residential Buildings (2004–2006)

Confined to object of origin

Confined to room of origin

Confined to floor of origin

Confined to building of origin

Beyond building of origin

Percent of Fires

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0

 33.7

 22.9

 8.1

 30.2

 5.2

Source: NFIRS 5.0 
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 6

Factors Contributing to Ignition

Table 3 shows the leading factor contributing to the ignition of intentionally set residential building fires is “playing 

with heat source” (26 percent). The category “playing with 

heat source” includes playing with lighters, matches, and 

other open flame or smoking materials. “Misuse of material 

or product” is the next leading factor at approximately 18 

percent. The remaining factors are “flammable liquid used 

to kindle fire” (8 percent) and “abandoned or discarded 

materials or products” (7 percent). Tied with the leading category is “other factors” (26 percent) which include 

unspecified components that did not fit into any other 

category of contributing ignition factors.

Table 3. Leading Factors Contributing to Ignition for Intentionally Set Fires in Residential 

Buildings (Where Factor Contributing Specified, 2004–2006)

Factors Contributing to Ignition Percent of Intentionally Set Fires in Residential Buildings

Playing with heat source 25.7

Misuse of material or product, other 17.8

Flammable liquid used to kindle fire 8.4

Abandoned or discarded materials or products 7.3

Other, unspecified factors contributing to ignition 25.7

Source: NFIRS 5.0 

Note: Includes only incidents where factors that contributed to the ignition of the fire were specified. Multiple factors contributing to fire ignition may be noted for each incident. 

Smoke Alarms 

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

limited in scope.

In forty-four percent of nonconfined intentionally set fires 

in residential buildings there were no smoke alarms present 

(Table 4). In another 23 percent of these fires, firefighters 

were unable to determine if a smoke alarm was present. 

Smoke alarms were present in only 33 percent of nonconfined intentionally set fires in residential buildings. Smoke 

alarms are known to have operated in 18 percent of intentionally set residential building fires. Smoke alarms failed 

to operate in 16 percent of intentionally set, nonconfined 

residential building fires where smoke alarms were present.

In 62 percent of confined intentionally set fires in residential buildings, the smoke alarm effectiveness was unknown 

(Table 5). Smoke alarms operated and alerted occupants 

in 16 percent of confined fires. In 22 percent of confined 

intentionally set residential building fires, the occupants 

were not alerted by the smoke alarm.7

 Note that the data 

presented in Table 4 and Table 5 are the raw counts from the 

NFIRS data set and not scaled to national estimates of smoke 

alarms in residential building intentionally set fires.
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 7

Table 4. NFIRS Smoke Alarm Data for Nonconfined Intentionally Set Fires in Residential 

Buildings (NFIRS, 2004-2006)

Presence of Smoke 

Alarms

Smoke Alarm 

Operational Status Smoke Alarm Effectiveness Count Percent

Present

Fire too small to activate smoke 

alarm 848 3.8

Smoke alarm operated

Smoke alarm alerted occupants, occupants responded 2,649 11.8

Smoke alarm alerted occupants, occupants failed to 

respond 158 0.7

No occupants 674 3.0

Smoke alarm failed to alert occupants 86 0.4

Undetermined 361 1.6

Smoke alarm failed to operate 1,215 5.4

Undetermined 1,443 6.4

None present 9,847 43.9

Undetermined 5,123 22.9

No Data 3 0.0

Total Incidents 22,407 100.0

Source: NFIRS 5.0

Note: The data presented in Table 4 are raw data counts from the NFIRS data set. They do not represent national estimates of smoke alarms in nonconfined intentionally set fires in residential buildings. They are 

presented for informational purposes. Total may not add to 100 percent due to rounding.

Table 5. NFIRS Smoke Alarm Data for Confined Intentionally Set Fires in Residential 

Buildings (NFIRS, 2004-2006)

Smoke Alarm Effectiveness Count Percent

Smoke alarm alerted occupants 353 15.5

Smoke alarm did not alert occupants 508 22.2

Undetermined 1,423 62.3

Total Incidents 2,284 100.0

Source: NFIRS 5.0

Notes: The data presented in Table 5 are raw data counts from the NFIRS data set. They do not represent national estimates of smoke alarms in confined intentionally set fires in residential buildings. They are 

presented for informational purposes. Total may not add to 100 percent due to rounding.

Examples

The following are some recent examples of intentionally set 

residential fires reported by the media:

•	 January 2009: Firefighters in Derry Township, 

Pennsylvania, dealt with six intentionally set fires that 

occurred between August 2007 and January 2009. 

Investigators stated that the fires were considered to be 

arson. Police are working with homeowners to set up 

neighborhood watches.8

•	 February 2009: A Conroe, Texas, family escaped a residential fire in their family home which they believe was 

intentionally set. Firefighters were able to control the 

fire within an hour. A preliminary investigation did not 

reveal anything of a suspicious nature, but the investigation is still being conducted.9

•	 February 2009: The Kenosha Fire Department 

responded to a residential fire in a Dayton Residential 

Facility. Investigation showed that a man intentionally set a blanket on fire in his living room. The facility 

smoke alarms went off and the fire was quickly controlled. The fire was contained to the room largely due 

to the building’s sprinkler system.10

•	 February 2009: Clemson University police and firefighters responded to an early-morning residence hall fire. 

The fire was believed to have been intentionally set. The 

sprinkler system successfully contained the fire, but the 

building had severe fire and water damage.11
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 8

Conclusion

Intentionally set residential fires have become the focus of 

increased attention within the State and Federal governments, local fire departments and State agencies, affected 

neighborhoods and communities, and the criminal justice system, largely because they account for and cause 

many injuries and deaths as well as property damage. 

Intentionally set fires account for 5 percent of all residential 

building fires. Intentionally set fires also account for 10 

percent of all fire deaths and 6 percent of all fire injuries in 

residential buildings. The challenge for communities and 

the fire service is to pinpoint the reasons why people set 

intentional fires in residential buildings and address these 

issues to prevent fires and severe property damage from 

occurring in the future. 

NFIRS Data Specifications for Intentionally 

Set Fires in Residential Buildings

Data for this report were extracted from the NFIRS annual 

Public Data Release (PDR) files for 2004, 2005, and 2006. 

Only version 5.0 data were extracted.

Intentionally set fires were defined as:

•	 Incident types 111 to 123:

Incident 

Type Description

111 Building fire

112 Fires in structure other than in a building

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 that incident types 113–118 do not specify if the 

structure is a building.

Incident type 112 is included as previous analyses 

have shown that incident types 111 and 112 are used 

interchangeably.

•	 Aid types 3 (mutual aid given) and 4 (automatic aid 

given) were excluded to avoid double counting of 

incidents.

•	 Property use 400 to 464:

Property 

Use Description

400 Residential, other

419 1 or 2 family dwelling

429 Multifamily dwelling

439 Boarding/Rooming house, residential hotels

449 Hotel/Motel, commercial

459 Residential board and care

460 Dormitory-type residence, other

462 Sorority house, fraternity house

464 Barracks, dormitory

•	 Structure type:

– 1 - Enclosed building

– 2 - Fixed portable or mobile structure

– Structure type not specified (null entry), and

•	 The USFA cause hierarchy was used to determine intentionally set fire incidents:12 http://www.usfa.dhs.gov/

fireservice/nfirs/tools/fire_cause_category_matrix.shtm.

To request additional information or to comment on this 

report, visit http://www.usfa.dhs.gov/applications/feedback/index.jsp

Notes: 

1 National estimates are based on 2004-2006 native version 5.0 data from the National Fire Incident Reporting System 

(NFIRS) and residential structure fire loss estimates from the National Fire Protection Association’s (NFPA’s) annual survey of 

fire loss. Fires are rounded to the nearest 100, deaths to the nearest 5, injuries to the nearest 25, and loss to nearest $million.

2 Residential buildings include, but are not limited to, one- or two-family dwellings, multifamily dwellings, boarding 

houses or residential hotels, commercial hotels, college dormitories, and sorority/fraternity houses.

continued on next page
TFRS Volume 9, Issue 8/Intentionally Set Fires in Residential Buildings Page 9

3 In the National Fire Incident Reporting System (NFIRS), version 5.0, a structure is a constructed item of which a building 

is one type. In previous versions of 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 NFIRS 5.0 has, therefore, changed to 

include 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 fires 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, 

incidents that have a residential property use, but do not have a structure type specified are presumed to be buildings.

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

and fire injury loss rates computed from NFIRS data alone. The fire death rate computed from national estimates would 

be (1,000*(290/18,100)) = 16.0 deaths per 1,000 intentional residential building fires and the fire injury rate would be 

(1,000*(850/18,100)) =47.0 injuries per 1,000 intentional residential building fires. In addition, NFPA has a separate 

estimate for intentionally set structure fires. The fire death rate computed from these estimates for intentional structure fires 

for 2006 would be (1,000*(305/31,000)) = 9.8 deaths per 1,000 intentional structure fires. Structure fire injuries are not 

reported. (NFPA, Fire Loss in the United States, September 2007).

5 Confined fires in NFIRS are small fire incidents that are limited in scope, confined to noncombustible containers, rarely 

result in serious injury or large content losses, and expected to have no significant accompanying property losses due to 

flame damage. This incident type differs from extent of flame spread confined to object of origin in the expectation of 

loss—a fire confined to the object of origin could still have significant property loss. An example of a confined fire is food 

on the stove where the damage is limited to the food and cooking container. 

6 For the purposes of this report, the time of the fire alarm is used as an approximation for the general time the fire started. 

However, in NFIRS, it is the time the fire was reported to the fire department.

7 In 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, or the smoke alarm was present and operated but the occupant was already aware of 

the fire.

8 “6 arsons in Derry leave residents, police on edge,” pressandjournal.com, February 18, 2009. http://www.pressandjournal.com/articleDetail.aspx?id=2202 (accessed March 5, 2009).

9 Howard Roden, “Conroe men escape residential fire,” hcnonline.com, February 12, 2009. http://www.hcnonline.com/

articles/2009/02/12/conroe_courier/news/fire0213.prt (accessed March 5, 2009).

10 Mark Hornickel, “Fire official: Blaze in Dayton Residential Facility intentionally set,” kenoshanews.com, February 12, 

2009. http://www.kenoshanews.com/news/fire_official_blaze_in_dayton_residential_facility_intentionally_set_4359862.

html (accessed March 5, 2009).

11 Anna Simon, “Probe continues into dorm fire: sprinklers extinguished early-morning blaze on sixth-floor of 10-story 

building,” Greenvilleonline.com, February 10, 2009.

http://www.greenvilleonline.com/article/20090210/PCN/902100320/1001/NEWS01 (accessed March 5, 2009).

12 USFA’s cause hierarchy is designed for structure fires; however, it can be used to determine certain causes for some specific types of fires.