1. Chapter 18 Fire Cause Determination

2. Fire Officer I Objectives
Identify the common causes of fire.
Explain when to request a fire investigator.
Describe how to find the point of origin of a fire.
Discuss the legal considerations of fire cause determination.

3. Fire Officer II Objectives
Discuss the nature of fire investigation.
Describe how to find the point of origin of a fire.
Describe how to determine the cause of the fire.
Describe the fire cause classifications.

4. Fire Officer II Objectives
Describe the indicators of incendiary fire.
Discuss arson.
Describe the documents and reports a fire officer must complete.

5. Fire Officer II Objectives
Describe how a fire investigation continues after fire official involvement has ended.

6. Introduction
An investigation is conducted to determine how a fire started.
Understanding the cause:
Helps prevent future fires
Helps determine if criminal acts were involved

7. Introduction
The incident commander is responsible for conducting the investigation.
The legal responsibility for conducting the investigation is defined by state or local legislation or regulations.

8. Common Causes of Fires
A relatively small number of causes are responsible for a large number of fires.

9. Requesting an Investigator
The fire officer should determine the point of origin and probable cause.
On small or routine incidents, this is the only investigation conducted.

10. Requesting an Investigator
A set of guidelines explains when to request an investigator:
Death or serious burn injury
Deliberate fire
Large-loss fire
Possible crime
© Stud Milne/AP Images

11. Fire Growth and Development
To determine the fire’s point of origin, the fire officer must understand fire behavior, growth, and development.
Three methods of heat transfer:
Conduction
Convection
Radiation

12. Disabled Built-in Fire Protection
May be encountered in fires involving industrial or commercial occupancies
Look for damage or vandalism:
Sprinkler hook-ups
Hose cabinets
Hard-wired smoke detectors
High-rise communication systems

13. Delayed Notification or Difficulty Getting to the Fire
Be alert for conditions that delay the fire department’s ability to get to the fire:
Malfunctioning keys or key cards
Vandalized doors
Materials blocking access
Points of origin in the attic, the basement, or a closet

14. Tampered or Altered Equipment
Document unusual conditions:
Indications of forcible entry
Altered electrical devices
Use of excessive fuel

15. Legal Considerations
The fire officer who investigated the fire may be called to testify in court.
May be challenged on issues of proper procedure

16. Searches
Typically no search warrant is needed to enter the fire scene, collect evidence, and determine the cause of a fire.
A warrant is required after fire origin and cause have been determined:
Administrative search warrant
Criminal search warrant

17. Securing the Scene If the fire officer suspects a crime has occurred:
Immediately request a fire investigator.
Secure the scene and maintain custody until the investigator arrives.

18. Evidence
Evidence: material objects and statements that are admissible as testimony in a court of law
Demonstrative evidence
Documentary evidence
Testimonial evidence

19. Evidence Artifacts could include:
Remains of the material first ignited
Remains of the ignition source
An item on which fire patterns are present

20. Evidence Must Be Protected
The investigator’s goal is to identify the point of origin and the cause of the fire.
Fire scene reconstruction: re-creating the physical scene before the fire occurred, either physically or theoretically

21. Evidence Must Be Protected
The investigator must locate, examine, and preserve evidence.
The fire officer must determine when to stop firefighting operations as part of this effort.
© Glen E. Ellman

22. The Nature of Fire Investigation
Fire investigation involves skill, technology, knowledge, and science.
Factual data must be compiled and analyzed.
Investigations must be systematic.
The origin must be determined before the cause is settled.

23. Finding the Point of Origin
Point of origin: exact location where a heat source and fuel came in contact
The fire investigator usually starts in the area where the least amount of damage occurred.

24. Finding the Point of Origin
To find the point of origin, the investigator analyzes:
Fire patterns left by the fire
Observations of witnesses
The physics and chemistry of fire initiation, development, and growth
Any location and circuit where electrical arcing has caused damage

25. Fire Patterns
The point of origin can often be identified by fire patterns.
Movement pattern: V- or U-shaped pattern
Intensity pattern: response of materials to the rate of heat release and flux
Courtesy of Eddie D. Smith/Unified Investigations & Sciences, Inc.

26. Fire Patterns
Char: blackened remains of carbon-based material after it burns
Helps determine:
Direction of fire spread
Apparent duration and intensity
© Vladimir Zanadvorov/ShutterStock, Inc.

27. Determining the Cause of the Fire
Cause: circumstances and factors that were necessary for the fire to occur
Determine the source of ignition.
Determine the fuel that was first ignited.
Determine the circumstances or human actions that allowed the ignition source and fuel to come together.

28. Source and Form of Heat Ignition
Source of ignition: energy source that caused the material to ignite
A competent ignition source has three properties:
Generation
Transmission
Heating

29. Material First Ignited
Type of material: nature of the material
Form of material: how the material was used

30. Ignition Factor or Cause
Could be a human act
Could be related to:
Mechanical failure
Poor or improper assembly of a device
Worn-out piece of equipment
Natural force

31. Ignition Factor or Cause
Failure analysis: logical, systematic examination of an item, component, assembly, or structure
Identifies the probability, causes, and consequences of potential and real failures

32. Fire Analysis
Scientific process of examining a fire occurrence to determine relevant facts:
Origin
Cause
Subsequent development
Responsibility for whatever occurred

33. Fire Analysis
The fire officer may need to construct a timeline of events.
Reproduced with permission from NFPA 921, Guide for Fire and Explosion Investigations, Copyright © 2008, National Fire Protection Association. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.

34. Conducting Interviews
Interview victims, witnesses, fire fighters, and suspected perpetrators.
Conduct separate interviews.
Use open-ended questions.
Conduct interviews at the fire scene.
Document interview information.

35. Vehicle Fire Cause Determination
Determine the fire’s point of origin.
Determine the cause.
Look for indications of arson.

36. Vehicle Fire Cause Determination
Consider sources of accidental ignition.
Note the make, model, and year of the vehicle, and the VIN.
Interview the driver(s).
© AlexKalashnikov/ShutterStock, Inc.

37. Wildland Fire Cause Determination
The amount and cost of wildland fire suppression efforts are increasing.
Different characteristics from structure fires:
Influenced by environmental conditions
Spread vertically through convection and horizontally through radiation

38. Wildland Fire Cause Determination
Factors affecting the rate of spread:
Type and density of material burning
Wind speed and direction
Humidity and fuel moisture content
Slope of the terrain and natural features
© AbleStock

39. Wildland Fire Cause Evidence
Campfire remains
Time-delay devices
Cigarette remains
Lighters
Multiple ignition points
Splintered trees
Fulgurites
Barrels used to burn trash
Fallen wires
Trees on power lines
Railroad tracks

40. Fire Cause Classifications
Accidental
Natural
Incendiary
Undetermined

41. Accidental Fire Causes
Leading causes of residential fires:
Unattended cooking
Smoking materials
Heating
Courtesy of the NJ State Fire Marshal’s Office, Arson/K-9 Unit.

42. Accidental Fire Causes
Pyrolysis lowers ignition temperature.
Consider it if the area of origin includes steam pipes, fluorescent light ballasts, flue pipes for a fireplace, or a wood-burning stove.
The most common electrical fire scenario is misuse by the occupant.

43. Natural Fire Causes Lightning Earthquakes Tornadoes Floods Hurricanes
Volcanoes

44. Incendiary Fire Causes
Intentionally started fires
Not necessarily arson
The fire officer may help determine the fire’s cause and origin and classify it as incendiary.
The prosecutor or grand jury decides whether it is arson.

45. Undetermined Fire Causes
Sometimes the cause of a fire cannot be determined.
Damage too extensive
Multiple causes can’t be ruled out
Not enough evidence or absence of any logical cause

46. Indicators of Incendiary Fires
Eliminate accidental and natural causes
Conditions indicating intentional fire:
Disabled built-in fire protection
Delayed notification/difficulty getting to fire
Accelerants and trailers
Multiple points of origin
Tampered or altered equipment

47. Accelerants and Trailers
Accelerants: agents used to initiate a fire or increase the rate of fire growth
Courtesy of Robert A. Corry/SceneInvestigator.com

48. Accelerants and Trailers
Trailers: materials used to spread a fire from one area of a structure to another
Paper towels
Gasoline or other flammable liquids
Decorative streamers
Newspapers

49. Multiple Points of Origin
Arsonists setting multiple ignition points
Materials falling from the ceiling and creating a secondary “U” or “V” pattern
Electrical surge causing ignition points at different locations

50. Arson
Crime of maliciously and intentionally or recklessly starting a fire
Highest rate of juvenile involvement compared with other serious felonies

51. Arson Motives Profit Crime concealment To collect insurance money
To facilitate extortion
To eliminate competition
Crime concealment
To destroy embezzlement records
To destroy evidence of other crimes
To distract responders while a crime is taking place

52. Arson Motives Excitement Spite/revenge Extremism Vandalism
To seek thrills, attention, or recognition
Spite/revenge
To express hatred or jealousy
Extremism
To cause a monetary loss to a business
To bring attention to a cause
Vandalism
To cause damage for its own sake

53. Documentation and Reports
All fires must be documented and reported according to the fire department’s standard procedures.
Most departments use the NFIRS or a variation.

54. Documentation and Reports
Basic report elements:
Incident number
Alarm time, date, and location
Property ownership
Building construction/occupancy type
Weather conditions
Responding units and personnel

55. Preliminary Investigation Document
Information included:
Receipt of alarm
Response to the incident
Accessibility at the scene
Fire suppression
Civilian contacts
Scene integrity

56. Investigation Report Information provided in chronological order:
Description of the structure before the event
Alarm notification information
Results of the fire scene examination

57. Investigation Report Attachments to this report:
Information obtained from witnesses and responders
Statements of evidence
Warrants
Sketches

58. Legal Proceedings
The fire officer may be called on to testify in court as a witness.
Prepare by reviewing:
Reports
Photographs
Diagrams
Previous depositions
© Corbis/age fotostock

59. Legal Proceedings Dress appropriately.
Follow the prosecutor’s directions.
Sit up with both feet on the floor.
Avoid gesturing.
Keep answers short and to the point.

60. Legal Proceedings Use language a jury can understand.
Be courteous and patient.
Be honest.
Do not hesitate answering questions.
Speak clearly and loudly.
If you do not remember, do not guess.

61. After the Fire Officials Are Gone
Many investigations continue long after the department has cleared the event.
The fire investigator is interested in determining the cause and origin.
Insurance company investigators may also be present.

62. Summary
To prevent future fires, it is important to understand the causes of past fires.
The fire officer should be able to determine a point of origin and a cause.
To determine the point of origin, the fire officer must understand fire growth and the three methods of heat transfer.

63. Summary
The fire investigator must take into account a citizen’s rights.
A fire officer who suspects a crime should request a fire investigator.
There are three types of evidence: demonstrative, documentary, and testimonial.

64. Summary
Fire scene reconstruction involves re-creating the scene before the fire occurred.
The first step in fire cause determination is to identify the point of origin.
Fire analysis involves examining fire occurrence.

65. Summary
Fire departments respond to more vehicle fires than structure fires.
Wildland fires are influenced by environmental conditions.
Fire cause classifications include accidental, natural, incendiary, and undetermined.

66. Summary
Arson is the crime of maliciously starting a fire or causing an explosion.
All fires must be properly documented and reported.
The fire officer often writes up a special report if the cause is incendiary or the circumstances are unusual.

67. Summary
In the investigation report, the information is provided in chronological order.
Many fire investigations continue long after the fire department has cleared the event.