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FIRE INVESTIGATIONS. Fred Herrera, CFI San Diego, CA (760) 805-3842 www.fredherrera.com fred@fredherrera.com. NATIONWIDE STATS. 2 million fires reported 9.4 billion dollars damage 5,000 fatalities 100 firefighter fatalities 25,500 injuries #1 cause of fires: cooking
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FIRE INVESTIGATIONS Fred Herrera, CFI San Diego, CA (760) 805-3842 www.fredherrera.com fred@fredherrera.com Copyright FHFI 2006
NATIONWIDE STATS • 2 million fires reported • 9.4 billion dollars damage • 5,000 fatalities • 100 firefighter fatalities • 25,500 injuries • #1 cause of fires: cooking • #1 cause of fire deaths: smoking Copyright FHFI 2006
BASIC FIRE SCIENCE Copyright FHFI 2006
Fire Triangle / Tetrahedron Copyright FHFI 2006
COMBUSTION • Heat • Fuel • Oxygen • Uninhibited chemical chain reaction • FOR FIRE SCENARIO • 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. • Density and surface area affect ignitability. • Heat source must have ability to transfer sufficient heat, for sufficient duration, to fuel source. Copyright FHFI 2006
Flammable / Combustible Flash point below 100 F Flammable liquid Gasoline, -44 F Flash point 100 F or above Combustible liquid Kerosene, 100 F Vapors burn, not liquid Fuel / air mixture LEL – Too lean UEL – Too rich Explosive range – Bingo! IGNITION OF LIQUIDS Copyright FHFI 2006
FIRE ORIGIN DETERMINATION • EXTERIOR EXAMINATION • INTERIOR EXAMINATION • Least damage to worst • Identify area of origin • RECONSTRUCTION • FIRE-SPREAD SCENARIO Copyright FHFI 2006
Accidental Appliance failure Natural Lightning Incendiary Fraud Undetermined Black holes Examine indicators Identify possible causes Identify heat, fuel & event Rule out other causes Determine cause Render opinion FIRE CAUSE DETERMINATION Copyright FHFI 2006
SYSTEMATIC APPROACHSCIENTIFIC METHOD • Recognize the need • Define the problem • Collect data • Analyze the data • Develop a hypothesis • Test the hypothesis • Select final hypothesis (determine cause) Copyright FHFI 2006
Resistance heating of a plug Copyright FHFI 2006
ARSON MOTIVES • Crime concealment • Spite / revenge • Fraud / Profit • Excitement • Extremist • Vandalism • Pyromania Copyright FHFI 2006
FIRE BOMBS Copyright FHFI 2006
DRUG LABS Copyright FHFI 2006
LAST CHANCE TO ASK! • ?? • ?? • ?? Copyright FHFI 2006
THE END! Copyright FHFI 2006