You are one of the on-call Fire Investigators for the Jamestown Municipal Fire Department. At 10:00 AM on Tuesday April 3rd you are notified that a structure fire has occurred at 75 South Street. You are assigned to conduct the cause and origin investigation along with your partner Lieutenant Brady. 75 South Street is a three story, two family residential structure located in a residential neighborhood. The dispatcher tells you the fire was in the rear of the building and it took the Fire Department about twenty minutes to extinguish it. The dispatcher also informs you that there is an investigator from the SafeWay insurance company responding to the scene. SafeWay holds the insurance policy for the building.
Part I. The Initial Investigation
1. You have been tasked with conducting a cause and origin investigation. Define “Cause” and “Origin” and provide examples of each.
2. While responding, you and Lieutenant Brady discuss using the scientific method to approach the investigation. What are the steps of the scientific method?
3. You are working for the Jamestown Municipal Fire Department as a public sector investigator. The SafeWay insurance company has sent a private sector investigator. What are the differences between public and private sector fire investigations?
4. Before you arrive on scene, you and Lt. Brady must ensure you are legally entering the property to begin your investigation. There are three main ways a public sector investigator can legally enter a building to begin an investigation. Define and explain them.
5. Your safety and the safety of your partner are always the top priority. What are some items you may wear to ensure you remain safe during the investigation When you arrive on scene, you will want to identify any potential hazards present during the investigation. What are some hazards for a fire investigator working at a residential structure fire?
Part II. The Exterior Examination
You and Lt. Brady arrive on the scene and meet with the Fire Department. The Fire
Department says a neighbor called in the fire after seeing it through her bedroom
window. Upon arrival the fire department said the whole back of the building was on fire.
They used hose lines to extinguish the fire. Review the pictures and provide answers
based on your knowledge of fire science.
6.
The “Exterior South” photo shows that heat energy traveled from the house to a
nearby car, likely through radiation. Radiation is one of the three methods of
heat transfer. Name the other two methods and provide examples of each.
7.
All the photos show that the fire moved well past the “Incipient Stage” which is
the first stage of fire growth. Name the other three stages of fire growth and
provide examples.
8.
To determine the cause and origin of the fire, the investigator must show how
all parts of the “Fire Tetrahedron” came together. Define the four components
of the “Fire Tetrahedron”.
9.
This is a “wood frame” building where the walls, floors and roof are all
constructed with wood. How does fire impact wood as oppose to non-
combustible construction materials such as steel or concrete?
10. One of the gases that is produced any time organic material burns is carbon
monoxide. How does carbon monoxide impact the human body?
11. What is the definition of “Fire”?
12. You conduct your exterior survey in a clockwise fashion and then work from
areas of “least damage” to areas of “most damage”. This is a systematic
approach to fire scene documentation. Why is it important to use a consistent
systematic method when documenting a fire scene?
13. Some neighbors are starting to become nosy and want to walk in the building to
see what happened. You know this could result in both “contamination” and
“spoliation”. Define these terms as they relate to fire investigation.
14. Lt. Brady suggests looking for evidence in the yard by conducting a grid search
or “gridding” the scene. Define this and explain why this method is beneficial.
15. Lt. Brady reminds you to use the methods explained in NFPA 921 standard.
What is NFPA 921 and why is it important?
Part III. The Interior Examination
After conducting a systematic exterior examination, you and Lt. Brady move to the
interior of the building. Review the photos and provide answers to the following
questions:
16. The photo labeled “Interior – Bedroom 2 – South Wall” shows a very clear “V”
burn pattern. How is a “V” burn pattern created and what information can it
provide investigators?
17. The photo labeled “Interior- Bedroom 2” shows that the wood ceiling joists have
no smoke or heat damage on them and could be called a “Protected Area”.
What is a “Protected Area” and why should fire investigators document them?
18. The photo labeled “Interior – Kitchen” shows heavy heat damage to the
cabinets near the ceiling, but almost no damage near the floor. How can this
happen?
19. “Interior – Bedroom 2” shows that the ceiling has collapsed down into the room.
“Layering” may be used to sift through this evidence. Describe this method.
20. At the conclusion of your investigation, you and Lt. Brady are able to classify
the fire as “Accidental”. Define and explain the other three possible
classifications used to categorize fires.
