Chapter 18 Fire Cause Determination

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.

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.

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

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

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

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.

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

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.

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

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

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

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

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

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

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

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.

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

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

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

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

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.

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.

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

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.

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.

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.

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

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

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

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

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

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.

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.

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

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.

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

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

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

Fire Cause Classifications Accidental Natural Incendiary Undetermined

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.

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.

Natural Fire Causes Lightning Earthquakes Tornadoes Floods Hurricanes Volcanoes

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.

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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.

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.

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.

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.

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.

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.

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.

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.

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.