Fire Origin and Cause Determination Flashcards
True or false, it is only the responsibility of the fire investigator to recognize the fire’s area of origin.
False, it is the job of every firefighter to recognize and protect the area of origin.
In most jurisdictions, whose responsibility is it to determine the cause of the fire?
The fire chief’s.
True or false, the fire chief must attend every fire to determine the fire cause.
False, the fire chief can delegate the authority of the investigation to a qualified fire officer or firefighter on scene.
If you are the first firefighters on the scene, what five things should you make a mental note about?
- Vehicles and people present at the scene.
- Whether doors and windows were open of closed
- Evidence of forced entry other than that of a firefighter
- Condition of the contents inside, if it looks normal, ransaked or too empty.
- Unsusual fire behaviour
True or false, it is encouraged to discuss the potential cause of the fire with other firefighters at the scene so that everyone can get fire investigation experience.
False, you should avoid talking about the cause incase anyone hears you and reports it in the news as a fact.
What is the only thing that you ought to say to a reporter regarding the cause of the fire?
“The fire is under investigation.”
True or false, an insurance investigator is allowed to condict heir investigation at the same time as the fire department fire investigator.
True
Where is the best place to look for the fire cause?
The area of origin
What is the best way to find the area of origin?
It is usually the place with the most fire damage
When looking for the area of origin, where is the best place to start your search?
Start at the unburned side of the house or at the outside if the whole structures is burned. Look for fire patterns to determine the area of origin.
What are the five interior fire patterns?
- V-shaped
- U-shaped
- Hourglass
- Circular shaped
- Inverted cone
What evidence of fire cause can be made from the outside of the structure?
- Building damage
- Ventilation patterns
- Means or ingress and egress
- Utilities
- Tire tracks or footprints
- Fuel cans
- Forcible entry
- Surveillance cameras at or around the scene
Which comes first; the interior or exterior examination?
Exterior
Which is usually more damaged in a structure fire; the floor or the ceiling?
ceiling
Lets say that you are in a hallway and to your left the charring is a darker black and to your right the charring becomes gradually less dark. Which direction is the area of origin likely to be?
To your left
True or false, multiple areas of intense burning means tha the fire was an arson.
False, it could also be an accidental fire that had some objects that burned intensely.
What six factors can affect the fire spread and should be evaluated by the fire investigator?
- Material and composition of objects in the house
- Building features that contribut or resist fire spread
- Ventilation openings
- Combustible materials present
- Fire suppression tactics
- Activation of fire suppression systems
True or false, burned long grass will fall towards the area of origin.
True
How should you approach a vehicle fire that you are trying to investigate, even if it is extinguished?
Use the same precautions as discussed in chapter 17
What is the competent ignition source?
The nheat source that ignited the fire.
What is an ignition sequence?
The ignition source and the material that first ignited. The history of the fire.
What three qualities must a competent ignition source have?
- Sufficient temperature
- Sufficient heat energy transfer to result in ignition
- Sufficient time to transfer the required amount of energy
Which are the easiest to ignite; gases, liquids or solids?
Gases, then liquids, then solids
What three qualities must the material first ignited have to be determined to be the material first ignited?
- Capable of being ingnited by the energy output of the identified ignition source
- Close enough to the ignition source to receive the energy from the ignition source
- Capable of absorbing sufficient energy to begin ignition
Why is surface to mass ratio important in determining the first fuel ignited?
Large pieces of fuel are very difficult to make catch fire, so the first fuel ignited must be someting small or easily ignited like liquid or gas.
Why is fuel orientation important in determining the first fuel ignited ?
Because if a piece of paper is vertical, it will burn faster and with more heat than if it were placed horizontally due to convective heat.
True or false, failure to act in order to prevent the ignition of a fire is still a contributor to ignition.
True it is called omission
What are the four types of fire causes?
- Accidental
- Incendiary
- Natural
- Undetermined
If a buuilding is completely destroyed in a fire and no cause can be found, what classification does it fall under?
Undetermined
If a hay bail decomposes and auto ignites is that a kind of ommission or is it natural causes?
Natural cause
Do the accounts of eye witnesses count as evidence?
Yes
What is direct evidence?
Evidence gathered using the senses at the time of fire ignition. Ex: watching someone lighting a car on fire, smelling gasoline being thrown on a fire instead of water. smelling propane in the air before a fire ignites.
True or false, Circumstantial evidence are facts that support an argument. like if someone is seen with a propane torch and then is seen running from an ignited building later.
True, it is not evidence that can convict someone automatically, but it can support an argument.
What kind of evidence do fire investigators most heavily rely on during investigations?
Circumstatial as they rarely see the fire themselves.
What is physical evidence?
Evidence that does not require a witness. if there is evidence of a forcible entry, it is likely that the fire waas caused by arson.
What is spoliation?
Evidence that is destroyed or ruined by someone that is responsible for its preservation.
