IFSTA Ch 29 Fire Investigations Flashcards
Company officers must not allow the ______ process to begin before the cause of the fire has been determined and any ______ protected.
overhaul; evidence
One of the most important aspects of fire investigation is awareness by company officers and unit members of the importance of _______ ______.
preserving evidence
Name the first step in the fire investigation process:
locate the point of origin
Who may be the most important sources of information about the point of origin of the fire:
those who reported the fire and those who fought it
Whether the fire is inside a structure or out in the wildland, what is an indicator of the point of origin
burn pattern left
Burn patterns tend to be ______ from the point of origin and are often what shaped:
vertical; V-shaped
Because the fire burns _____ at the point of origin, it is usually the area of ____ _____ ____.
longer; greatest fire damage
Vehicle fires fall into one of two broad catagories:
- Those that occur while the vehicle is driven
2. Those that occur while the vehicle is parked
What are the most often causes of vehicle fires while being driven:
- Mechanical malfunctions
- Electrical malfunctions
- Carelessness with smoking materials
What are the common locations for vehicle fires due to mechanical malfunctions:
- Engine compartment
- Exhaust system
- Wheel and brake systems
For a parked vehicle fire, why would a malfunction of mechanical or electrical means not ignite while it was moving?
The ignition temperature was cooled due to the wind keeping temperature lower, until parked.
In general wildland fires spreads away from the point of origin in three predictable ways:
- spreads faster uphill
- spreads faster with the wind against it
- spreads faster in fine fuels (grass) than in heavier fuels (timber)
The depth of char for wildland fires indicates the direction ____ ____ the fire spread
from which
How are fires generally classified as (per NFPA 921 Guide for Fire and Explosion Investigations):
Accidental;
Natural;
Incendiary;
Undetermined
What are fires that did not result from intentional or malicious human activity?
Accidental Fires
Fires that involve human activity and are deliberately set (malicious or not) are classified as:
Incendiary fires
T/F - the term suspicious should be used as a fire cause classification
F - if the cause cannot be determined with a reasonable certainty, it should be listed as undetermined
What is an accidental fire that is termed as a ‘friendly fire’?
Intentionally set fires for a legitimate purpose, such as burning leaves and the fire gets out of control and spreads.
Why do fatalities occur with smoking-related accidental fires?
The occupant, often is incapacitated by alcohol or other drugs and either falls asleep or passes out.
What is a pyrophoric ignition?
The ignition temperature is gradually lowered until autoignition occurs. Such as wood framing in walls adjacent to metal fireplace boxes and flues.
T/F - the mere presence of electrical wiring or appliances near the point of origin means that the fire was electrical in nature.
F - it should be considered along with other possible sources of ignition, due to the heat generated by electrical wiring and equipment
What is the most common cause of electrical fires
Misuse of the electrical system by the bldg occupants (use of lightweight extension cords or zip cords and the use of a multiple-outlet device known as an octopus)
What is the ‘most’ important thing to check during fire investigation with electrical fires?
The position of the power switch on any appliance found at the point of origin
Main fuses or circuit breakers that are melted are from what type of fire?
Natural fires - lightning related fires
