Copyright FHFI 2006 FIRE INVESTIGATIONS FIRE INVESTIGATIONS Fred Herrera, CFI San Diego, CA (760)
Copyright FHFI 2006 NATIONWIDE STATS 2 million fires reported 2 million fires reported 9.4 billion dollars damage 9.4 billion dollars damage 5,000 fatalities 5,000 fatalities 100 firefighter fatalities 100 firefighter fatalities 25,500 injuries 25,500 injuries #1 cause of fires: cooking #1 cause of fires: cooking #1 cause of fire deaths: smoking #1 cause of fire deaths: smoking
Copyright FHFI 2006 BASIC FIRE SCIENCE
Copyright FHFI 2006 Fire Triangle / Tetrahedron
Copyright FHFI 2006 COMBUSTION Heat Heat Fuel Fuel Oxygen Oxygen Uninhibited chemical chain reaction Uninhibited chemical chain reaction FOR FIRE SCENARIO FOR FIRE SCENARIO HEAT, FUEL, OXYGEN & EVENT HEAT, FUEL, OXYGEN & EVENT
Copyright FHFI 2006
HEAT TRANSFER
Copyright FHFI 2006 IGNITION OF SOLIDS Material must be pyrolyzed, or chemically decomposed, by the application of heat. Material must be pyrolyzed, or chemically decomposed, by the application of heat. Density and surface area affect ignitability. Density and surface area affect ignitability. Heat source must have ability to transfer sufficient heat, for sufficient duration, to fuel source. Heat source must have ability to transfer sufficient heat, for sufficient duration, to fuel source.
Copyright FHFI 2006 IGNITION OF LIQUIDS Flammable / Combustible Flammable / Combustible Flash point below 100 F Flash point below 100 F Flammable liquid Flammable liquid Gasoline, -44 F Gasoline, -44 F Flash point 100 F or above Flash point 100 F or above Combustible liquid Combustible liquid Kerosene, 100 F Kerosene, 100 F Vapors burn, not liquid Vapors burn, not liquid Fuel / air mixture Fuel / air mixture LEL – Too lean LEL – Too lean UEL – Too rich UEL – Too rich Explosive range – Bingo! Explosive range – Bingo!
Copyright FHFI 2006 FIRE ORIGIN DETERMINATION EXTERIOR EXAMINATION EXTERIOR EXAMINATION INTERIOR EXAMINATION INTERIOR EXAMINATION Least damage to worst Least damage to worst Identify area of origin Identify area of origin RECONSTRUCTION RECONSTRUCTION FIRE-SPREAD SCENARIO FIRE-SPREAD SCENARIO
Copyright FHFI 2006 FIRE CAUSE DETERMINATION Accidental Accidental Appliance failure Appliance failure Natural Natural Lightning Lightning Incendiary Incendiary Fraud Fraud Undetermined Undetermined Black holes Black holes Examine indicators Examine indicators Identify possible causes Identify possible causes Identify heat, fuel & event Identify heat, fuel & event Rule out other causes Rule out other causes Determine cause Determine cause Render opinion
Copyright FHFI 2006 SYSTEMATIC APPROACH SCIENTIFIC METHOD Recognize the need Recognize the need Define the problem Define the problem Collect data Collect data Analyze the data Analyze the data Develop a hypothesis Develop a hypothesis Test the hypothesis Test the hypothesis Select final hypothesis (determine cause) Select final hypothesis (determine cause)
Copyright FHFI 2006
Resistance heating of a plug
Copyright FHFI 2006
ARSON MOTIVES Crime concealment Crime concealment Spite / revenge Spite / revenge Fraud / Profit Fraud / Profit Excitement Excitement Extremist Extremist Vandalism Vandalism Pyromania Pyromania
Copyright FHFI 2006
FIRE BOMBS
Copyright FHFI 2006 DRUG LABS
Copyright FHFI 2006 LAST CHANCE TO ASK! ?? ??
Copyright FHFI 2006 THE END!