Essentials of Fire Fighting 6th Edition

Firefighter I !

Chapter 19 — Fire Origin and Cause Determination

1

!! Explain ways to recognize obvious signs

of the area of origin.

Learning Objective 1

19–2

2

The area of origin contains several pieces of important information.

19–3

3

Debris on scene contains fire cause indicators and must remain in place.

19–4

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You must control evidence and remember information from the incident as much as possible.

19–5

5

CAUTION

You should minimize fire suppression and overhaul activities that could destroy important evidence regarding the origin and cause of the fire.

19–6

6

Several factors will influence locating the area of origin and the overall success of the investigation.

19–7

7

The search for area of origin at a structure fire begins outside.

19–8

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You should know actions to take when the origin cannot be determined.

19–9

9

Preliminary assessment and exterior examination require specific tasks.

19–10

10

The interior examination begins in the area of least damage and works toward the area of greatest damage.

19–11

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11

Charring on floors and vertical surfaces can indicate useful information.

19–12

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12

Area of origin and fire spread factors should be closely examined.

19–13

13

Total structural fire loss presents unique investigation challenges.

19–14

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Exterior fires involve several different types of materials.

19–15

15

Ground cover fires require specific understanding of several concepts.

19–16

16

Fire burns in equal directions when on flat ground and without wind.

19–17

17

The rate and direction of spread of ground cover fires are affected by several components.

19–18

18

Ground cover fires require specific understanding of several concepts.

19–19

19

Finding the area of origin for vehicle fires is similar to the structural process.

19–20

20

Vehicle fires require knowledge and practice of several safety guidelines.

19–21

21

WARNING

Do not attempt to access or examine a vehicle unless you know how to do so safely.

19–22

22

REVIEW QUESTION

!! What ways can a Firefighter I recognize obvious signs of a fire’s area of origin?

19–23

23

!! Describe the relationship between fire

cause classifications and cause determination.

Learning Objective 2

19–24

24

Fire cause determination is a critical step in the investigation process.

19–25

25

The National Fire Incident Reporting System (NFIRS) reports several causes of fires in structures.

19–26

(Cont.)

26

The National Fire Incident Reporting System (NFIRS) reports several causes of fires in structures.

19–27

(Cont.)

27

The National Fire Incident Reporting System (NFIRS) reports several causes of fires in structures.

19–28

28

There are four types of fire cause classifications.

19–29

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Trai

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29

There are several obvious signs of cause you should look for.

19–30

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DISCUSSION QUESTION

!!What are some visual signs that may determine the area of origin for ground cover fire?

19–31

31

Absence of an obvious ignition source can help investigations.

19–32

32

REVIEW QUESTION

!! What is the relationship between fire cause classifications and cause determination?

19–33

33

!! Recognize signs of arson.

Learning Objective 3

19–34

34

You will need to provide information if an incendiary or undetermined initial cause is indicated.

19–35

(Cont.)

35

You will need to provide information if an incendiary or undetermined initial cause is indicated.

19–36

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Additional information should also be gathered to assist investigators.

19–37

(Cont.)Courtesy of Donny Howard

37

Additional information should also be gathered to assist investigators.

19–38

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Conditions should also be observed to provide information for investigators.

19–39

(Cont.)

39

Conditions should also be observed to provide information for investigators.

19–40

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40

Conditions should also be observed to provide information for investigators.

19–41

(Cont.)

41

Conditions should also be observed to provide information for investigators.

19–42

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REVIEW QUESTION

!! How can a Firefighter I recognize signs of arson?

19–43

43

!! Describe the importance of

preserving evidence.

Learning Objective 4

19–44

44

!! Explain techniques for

preserving evidence.

Learning Objective 5

19–45

45

Preserving evidence requires understanding certain principles.

19–46

46

There are several important aspects of protecting the fire scene.

19–47

47

Establishing a scene perimeter requires specific knowledge.

19–48

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There are several ways to establish perimeters that are both recognizable and enforceable.

19–49

49

Procedures for criminal investigations also impact scene security practices.

19–50

50

There are several techniques used to preserve evidence.

19–51

(Cont.)

51

There are several techniques used to preserve evidence.

19–52

52

Overhaul operations can be detrimental to an investigation.

19–53

53

Even when a scene is secure, contamination or spoliation can occur.

19–54

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Follow local procedures when finalizing operations and investigations.

19–55

55

REVIEW QUESTION

!! What are some techniques firefighters can use to preserve evidence?

19–56

56

• One of the most important responsibilities is protecting evidence.

• Use appropriate caution in the area of origin.

• A thorough investigation can be conducted to determine the exact cause of the fire.

Summary

19–57

57