Four features of the investigation:
Cause of fire or explosion
Cause of damage to property
Cause of bodily injury / loss of life
Degree to which human fault contributed
Four classifications of cause:
Accidental
Natural
Incendiary
Undetermined
Should a fire ever be classified as "suspicious?
No. Suspicious is not an appropriate term to describe the unexplained.
What is failure analysis?
A logical, systematic examination of an item, component, assembly, or structure and it splace and function within a system, conducted to identify and analyze the probability, causes, and consequences of potential and real failures.
What are hard times?
Incidents with a known exact time. These include dispatch times and other documented times.
What are soft times?
Witness statements with approximate times, other observations with approximations.
What are benchmark events?
The foundation of the timeline. Includes events related to cause, spread, detection, or extinguishment of the fire.
Micro VS Macro times:
Macro can be as far as months or years before the fire, and Micro are small and narrow parts of the timeline.
What does FMEA stand for?
Failure Mode and Effects Analysis - a graphical method or technique used to determine causes and effects leading to the fire. Similar to Fault trees.
Mathmatical and Engineering models for fire investigation:
Heat Transfer models
Flammable gas Concentrations
Hydraulic Analysis (sprinkler failure)
Structural analysis
Egress analysis
Fire dynamis (fire growth)
What is a BLEVE?
Boiling Liquid Expanding Vapor Explosion
What are the basic types of explosions?
Mechanical
Chemical
Nuclear
Deflagration VS Detonation
Deflagration = less than the speed of sound
Detonation = Greater than the speed of sound, more than 1,100 FPS
What are the characteristics of Low order damage?
Slow pressure rise, pushing, bulging damage
What are the characteristics of high order damage?
Rapid pressure rise, shattering, pulverizing
What is a seated explosion?
Explosion with a crater of damage. Generally characterized by high pressure and rapid pressure rise. Explosives, steam boilers, and highly confined fuel gases.
What is a nonseated explosion?
Dispersed or diffused fuels with moderate pressure rise and subsonic (less than the speed of sound) velocities.
What is a backdraft?
Smoke explosion from an oxygen deprived fire. Oxygen is introduced to the room mixes with the fuels and ignites and burns fast enough to produce low-order damage.
What are some common high explosives?
TNT
ANFO
RDX
PETN
What are some incendiary fire indicators?
Multiple Fires
Trailers
Lack of expected fuel load (fire damage not consistent with existing fuel)
Lack of expected ignition sources
Exotic accelerants
Unusual fuel load or configuration
Burn injuries
Incendiary devices
Other factors not directly related to combustion, but still indicators of incendiary fire:
Remote locations with blocked view
Fires near service equipment and appliances
Removal/Replacement of contents prior to fire
Blocked entry
Sabotage to the structure or fire protection
Opening windows and exterior doors
What are some Evidentiary factors to consider?
Geographical (clusters)
Temporal frequency
Materials and methods (using the same firesetting method)
Financial stress
History of code violations
Fires at additional properties, same owner
Overinsured property
What are some timed opportunities?
Natural conditions (flood, hurricains, etc)
Civil unrest
Fire Dept unvailible
What are motives for firesetting?
Vandalism
Excitement
Revenge
Crime Concealment
Profit
Extremism
Carbon monoxide poisining causes what color of the skin?
Cherry-pink
What are the different degrees of burns?
1st degree, reddening of the skin
2nd degree, blistering
3rd degree, full-thickness damage to skin
4th degree, damage to fat/muscle and charring of tissue
What should you document on an appliance in the area of origin?
Controls
Bonding/grounding
Position of moving parts
Clocks
Power supply
Fuel supply (gas)
What identifying info should you get for each appliance?
Manufacturer
Model Number
Serial Number
Date of manufature
Name of product
Warnings
Recommendations
What is an exemplar?
A duplicate object, such as an appliance, obtained for testing purposes.
Types of heat cutoff devices:
Fluid pressure
Bimetal
Expanding metal
Melting
Motion switch (tip over)
What do fluorescent lights and HID lights have in common?
They all have ballasts, which can fail and cause a fire.
What are ignition sources in vehicles?
Open flames (backfire)
Electrical sources
Hot surfaces (exhaust)
Mechanical sparks (broken parts)
Smoking materials
What are the two basic fuel systems in a car?
Low pressure and high pressure.
Low pressure = 3-5 PSI, Carbuerated
High pressure = 35 - 70 PSI, fuel injected
Wildfires have what two types of fuel?
Ground fuels
Arial fuels
Sometimes:
Ground, surface, and crown
Three classifications of wind:
Meterological wind (normal wind)
Diurnal wind (solar heating / nightime cooling)
Fire winds
What is the fire head?
Portion of the fire that is moving most rapidly
What is the fire heel?
Opposite of the head, less intense
What are the causes of wildfires?
Lighting
Spontaneous heating
Campsite
Smoking
Debris burning
Sunlight and glass refraction
Incendiary
Juvenile
Fireworks
Controlled burn
Vehicles
Railroad
What are some search patterns?
Grid
Spiral
Strip
Area