Unit 6: Fire Scene Investigation Flashcards
Proper scene investigation consists of:
Establishing area of origin.
Identifying the competent ignition source.
Identifying circumstancesthat brought the fuel
and the ignition sourcetogether.
• Use a systematic approach.
– The same method every time, regardless of
size or type of fire event.
• Usually work from areas of least to most
damage.
You will always use the ______________
as part of your systematic approach.
Scientific Method
Use the scientific method to:
Identify the problem. – Define the problem. – Collect data. – Analyze data. – Develop hypothesis. – Test hypothesis.
— hypothesis developed before data collection.
Presumption Bias
— a premature conclusion
without consideration of all data; typically
based on previously formed assumption(s).
Expectation Bias
— only collecting data to
support your hypothesis.
Confirmation Bias
CRITICAL DATA POINTS FOR
ORIGIN DETERMINATION
- Witness statements.
- Fire patterns.
- Arc mapping.
- Fire dynamics
As fire spreads, wire may arc
“upstream” but would not arc
____________
“down stream”
_________________ is the unintentional
contamination of scene or evidence during
examination, collection, storage or
transport.
Cross-contamination
scene investigation
Exterior Scene photos (address sign) Document Door and Window conditions Aerial photos Exposure Documentation Examine transformer Electric meter/ Gas Meter HVAC components Fire Protection Systems location and condition of smoke alarms
Interior investigation
Floor Plan and layout Locks, Windows and Doors burn patterns arc mapping switches, outlets breakers water heater
• \_\_\_\_\_\_\_\_\_\_ is that which sustains combustion beyond the initial ignition source. • Example: The potential ignition source is the cigarette. The first fuel ignited is that paper
First Fuel ignited
CAUSE DETERMINATION:
HYPOTHESES LITMUS TEST
• Is the ignition source competent for the first
fuel ignited?
• Is time required for ignition consistent with
timeline?
• What circumstances brought the ignition
source in contact with the fuel?
• What failure modes were required for event?
• Fire origin area identified. • All accidental ignition sources eliminated. • Samples are negative. • Competent ignition source not found. • Infer open flame used to ignite first fuel.
NEGATIVE CORPUS EXAMPLE
