property and appliance fires - jensen hughes · 2015/10/13 · senior electrical engineer •b.s....

Property and Appliance FiresKenneth G. Rice

CFI, CFEI, CVFI, TIFIREE, PI, CFM, CBO, Senior Fire Investigator Sebastian Scheiff

PE, CFEI, Electrical Engineer

A very special thanks to

• Craig Harris• Dan Purcell

11/9/2015 Copyright CASE Forensics 2015. All Rights Reserved 2

Agenda• 12:45pm – 1:40pm

– Classroom• Introductions• Appliance Fires Overview• Investigation, Site Evidence and Analysis

• 1:40pm – 2:40 pm – Flammable Pad / Outside

• Property Fire/Flashover Demonstration• Scene Inspection / Diagramming

• 2:40pm‐3:30pm– Classroom

• CASE Studies• Property Fires and Structural Safety• Q&A


Ken RiceCFI, CFEI, CVFI, TIFIREE, PI, CFM, CBOSenior Fire Investigator • Glendale Law Enforcement Training Academy – National

Emergency Training Center• New Castle School of Trades – Advanced Automotive

Technology• Graduate, National Fire Academy, Emittsburg, MD• Certified Fire and Explosion Investigator, NAFI• Certified Fire Investigator, IAAI• Certified Vehicle Fire Investigator, NAFI• Licensed Unarmed Private Investigator, AZ• Licensed Unarmed Private Investigator, MT• Licensed Unarmed Private Investigator, OR• Licensed Unarmed Private Investigator, WA


Ken RiceCFI, CFEI, CVFI, TIFIREE, PI, CFM, CBOSenior Fire Investigator • Certified Fire Marshal, ICC• Certified Building Official, ICC• Certified Commercial Building Inspector, ICC• Certified Residential Building Inspector, ICC• Certified Fire Inspector I & II, ICC• Certified Fire Plans Examiner, ICC• Certified Fire Code Official, ICC• Certified Housing Code Official, ICC• Certified Property Maintenance & Housing Inspector, ICC• Certified Zoning Inspector, ICC• Code Enforcement Administrator, AACE• Code Enforcement Officer, AACE• Property Maintenance & Housing Inspector, AACE• Zoning Enforcement Officer, AACE• General Instructor, AZPOST• Maricopa County Arson Task Force• Technician, Institution of Fire Engineers11/9/2015 Copyright CASE Forensics 2015. All Rights Reserved 5

Sebastian ScheiffPE, CFEISenior Electrical Engineer

• B.S. in Electronics Engineering Technology, Western WA Univ.

• A.A. in Technical Arts, Skagit Valley College• Registered Professional Engineer, state of WA• Certified Fire and Explosion Investigator, NAFI• Hazardous Waste Operations and Emergency Response (HAZWOPER) Certification, CSOTI


APPLIANCE FIRESOverview

Appliance Fires

• Almost any appliance plugged into 120 VAC has the ability to fail and start a fire in some manner


Receptacles

• Contact resistance can deteriorate over time• “Back Fed” (push‐in) type receptacles have a higher incidence of failure

• Must have arcing


GFCI Failures

• Ground Fault Circuit Interrupters (GFCI) can fail


Common Residential Appliances• Toaster• Range/Oven• Coffee Maker• Electric Can Opener• Refrigerator• Dishwasher• Microwave Oven• Portable Space Heater• Electric Blanket• Window Air Conditioning Unit• Hair Dryer/Curler• Clothes Iron• Clothes dryer• Consumer Electronics• Lighting


Appliance Fires: Toaster Example


Appliance Fires: Toaster

• Are there any visible differences between the two bread slots?

Copyright CASE Forensics 2015. All Rights Reserved 1311/9/2015


• Are there any visible differences between the two bread slots?



• Fire Starter / Human Shocker


Appliances Fires: Component Failures • Common Component Failures in Appliances

– Relocatable Power Taps (Power Cords)– Batteries– Overcurrent Protection– Switches

• Levers, toggle, knobs– Temperature (expanding metal, bimetal, fluid pressure, melting)

• Thermal Cutouts (TCOs), Thermostats, Limit Switches– Solenoids/Relays– Transformers– Motors– Heating Elements– Lighting– High Intensity Discharge (HID) Lighting– Miscellaneous

• Timers, Thermocouples


Relocatable Power Taps (power strips, surge protectors, extension cords)

• Component Failures– Plastic Body–Metal Body–Metal Oxide Varistor (MOV)–Multiple Outlets

Copyright CASE Forensics 2015. All Rights Reserved 1711/9/2015

Relocatable Power Tap Disassembled


Exemplar Circuit Board and MOV


MOV Disk


MOV Failure


Failed MOV


Capacitor Failures


Capacitor Internals


Capacitor Winding


Motor With Canopy


Failed Motor


Capacitor with Wax


Waxy Exudate


Capacitor with Wax


Capacitors Ignited and Sustained Flaming Combustion


High Resistance Connection


INVESTIGATION & SITE EVIDENCE ANALYSIS

Overview

Investigation: NFPA 921 Guide for Investigators Fire and Explosion (2011 Edition)• General Definitions

– 16.1* General. During the course of any fire investigation, the fire investigator is likely responsible for locating, collecting, identifying, storing, examining, and arranging for testing of physical evidence. The fire investigator should be thoroughly familiar with the recommended and accepted methods of processing such physical evidence.

– 11.5.1.1 Rules of evidence regulate the admissibility of proof at a trial. The purpose of rules of evidence is to ensure that the proof offered is reliable. The goal of every fire investigation is to produce reliable documents, samples, statements, information, data, and conclusions. It is not necessary that every fire investigator become an expert on rules of evidence, If the practices and procedures recommended within this guide are complied with, the results of the investigation should be admissible.


Investigation: NFPA 921 Guide for Investigators Fire and Explosion (2011 Edition)• General Definitions

– 3.3.55 Failure Analysis. A logical, systematic examination of an item, component, assembly, or structure and its place and function within a system, conducted in order to identify and analyze the probability, causes, and consequences or potential and real failures.

– 3.3.62 Fire Investigation. The process of determining the origin, cause, and development of a fire or explosion.

– 3.3.144 Scientific Method. The systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formation and testing of a hypothesis.



Investigation:Scientific Method

Investigation: NFPA 921 Guide for Investigators Fire and Explosion (2011 Edition)• General Definitions, con’t.

– 3.3.9 Area of Origin. A structure, part of a structure, or general geographic location within a fire scene, in which the “point of origin” of a fire or explosion is reasonably believed to be located.

– 3.3.127 Point of Origin. The exact physical location within the area of origin where a heat source and fuel interact, resulting in a fire or explosion.

– 3.3.22 Cause. The circumstances, conditions, or agencies that brought about or resulted in the fire or explosion incident, or bodily injury or loss of life resulting from the fire or explosion incident.

– 17.1.2 Determination of the origin of the fire involves the coordination of information derived from one or more of the following:• Witness information• Fire Patterns• Arc Mapping• Fire Dynamics


NFPA 921 – Guide for Investigators Fire and Explosion (2011 Edition)• Chapter 24.6 – Common Residential Appliances

– Range/Oven– Coffee Maker– Toaster– Electric Can Opener– Refrigerator– Dishwasher– Microwave Oven– Portable Space Heater– Electric Blanket– Window Air Conditioning Unit– Hair Dryer/Curler– Clothes Iron– Clothes dryer– Consumer Electronics– Lighting


Investigation: NFPA 921 Guide for Investigators Fire and Explosion (2011 Edition)

• Additional Common Residential Appliances– Cell phone batteries/chargers– Rechargeable batteries/chargers – power tools– Power strips/relocatable power taps– Anything that is energized with a 120V/240V AC or DC power source can be a potential source of ignition


What happened?


Investigative steps• Initial Scene Inspection

– Examine the loss scene from least damage to most damage

– Digital Photography – Begin burn pattern analysis and fire scene diagramming

– Collect & preserve evidence• Middle

– Scientific Method• End

– Scientific Opinion


Investigation: Evidence ev∙i∙dence /ˈevədəns/

– noun• That which tends to prove or disprove something; ground for belief; proof.

• Something that makes plain or clear; an indication or sign:– His flushed look was visible evidence of his fever.

• Law. data presented to a court or jury in proof of the facts in issue and which may include the testimony of witnesses, records, documents, or objects.

– verb (used with object), evidenced, evidencing.• To make evident or clear; show clearly; manifest:

– He evidenced his approval by promising his full support.• To support by evidence:

– He evidenced his accusation with incriminating letters.– Idioms

• 6. in evidence, plainly visible; conspicuous:– The first signs of spring are in evidence.


Investigation: Evidence

• How can it help or hurt your case?– Provides physical proof of your theory.– Can eliminate other causes/failures.– Analysis by unqualified expert.


Investigation: Evidence

• What should you never, ever do with evidence?– Take it apart, or destructively examine, without consent from all parties.

– Touch or move if it is not your place to do so.– Fail to file proper chain of custody paperwork.


Site Evidence


Properly Collecting Evidence

• When is it okay to collect the evidence?– If the evidence will be compromised by leaving it at the scene.

– After it has been documented (photos/sketches).



• Is there a such a thing as “too much evidence”?



• What is the proper way to preserve evidence?



• Minimum supplies needed– Disposable gloves– Camera– Lined cans– Plastic bags/shrink wrap– Evidence labels


Documentation

• What is documentation?– Chain of custody paperwork– Evidence labels/tags– Photographs


Documentation


Evidence Preservation


• Overhaul and fire suppression can be destructive

Evidence preservation begins immediately• Examining the loss scene

– The loss scene needs to be investigated by the local jurisdiction having authority, which may be conducted in conjunction with private fire investigators

– The loss scene can change quickly due to work of contractors, employees, etc.


Avoiding potential issues

• An investigative firm should have the following– Procedures for handling evidence that minimize the risk that evidence is discarded or damaged

– Adequate storage facilities– Durable bags, boxes, and shrink wrap– Individual tracking numbers for each item of evidence


Easy To Lose Crucial Items

• Many parts can be camouflaged by their surroundings

• If small “crucial” parts are displaced, the entire case can be jeopardized


Easy to Lose Crucial Items

• Many small electrical components can easily blend in with fire debris

• Gypsum wall board forms “white mud”• Investigators need to have keen eye sight and an understanding of what to look for


Spoliation • The National Fire Protection Association’s 921 guidelines

are the standard for fire investigation.

• “Spoliation of evidence refers to the loss, destruction, or material alteration of an object or document that is evidence or potential evidence in a legal proceeding by one who has the responsibility for its preservation. Spoliation of evidence may occur when the movement, change or destruction of evidence or the alteration of the scene significantly impairs the opportunity of other interested parties to obtain the same evidentiary value from the evidence, as did any prior investigator.” – (Chapter 11.3.5.)


Spoliation

• How can you avoid a claim of spoliation?– Do not destructively examine.– Do not move evidence until all parties have opportunity to view scene.

– Store with care.– Don’t allow the restoration company, insured, etc. to rehab scene before exam.


LIVE BURN DEMONSTRATION

Property Fire/FlashoverScene Diagramming

Transition to Property Fire Area

• Transition Break• Meet at Flam Pad, Outside


CASE STUDYCommercial Building Fire

CASE Study: Fish Tank Heater Fire


Background• Single Story Commercial Building Fire 2008, Building Destroyed

• Day of loss– Space Heater had not been used– Staff unaware of any electrical problems in the building. – Lights shut off – except for the incandescent “can” lights above the desk,

• History– 2001 Lobby Remodel

• Initial investigation focused on fluorescent fixtures abandoned in a previous false ceiling following remodel.


Initial Suspected Area of Origin


Items in the Lobby• Lobby Furnishings

– Small beverage refrigerator,– Two large sofas– Two leather sofa chairs– Coffee table– Serving table– Aquarium– Reception desk

• Desk area– Computer on the floor – Three monitors – Printer– Remote telephone answering system,– Small space heater under the desk



Aerial view North wall of the building shows the approximate location of the fish tank (bluebox) and the location where the Fire Marshal selected the origin (red circle).

Char Patterns

• Visible char patterns were observed against the north concrete wall on the wood furring studs behind the aquarium.

• No char patterns were observed on the east wall wood studs.

• The west side wall between the lobby and the conference room was burned to the floor plate.


Char Patterns



Aerial view Location of the fish tank and the conduit supplying power to the fish tank which ran over head in the attic space.

Area of Aquarium ‐ East View


Area of Aquarium ‐ North View


Electrical Examination

• The electrical distribution panels were examined. – Due to the extensive fire damage to the conduit, the branch circuits could not be traced.

• Arc mapping for most of the scene was unsuccessful – Conductors were damaged or eliminated during the fire.


Arc Mapping• However, arc mapping was instrumental in determining the cause of the fire. – The EMT conduit which supplied power to the fish tank receptacle ran overhead and passed through the fire department’s suspected area of origin.

– No arcing was found in the conductors within the EMT

– Arcing was found within the fish tank heater. • Therefore, the arcing in the fish tank heater must have preceded the fire damage in the attic space in the adjacent office.


Fire Cause Determination

• The cause of the fire was determined to be the failure of the aquarium heater which resulted in electrical arcing and ignition of nearby plastic.


How did the Aquarium Fail??• Evidence Examination

– During the first examination, evidentiary items were carefully inspected and eliminated as potential ignition sources.

– Among many other items, the filter tank for the aquarium was examined. • The filter tank was located on the left side under the main aquarium, inside a wooden cabinet that supported the tank.

• The filter tank was made of clear acrylic plastic.• The filter tank was separated into two compartments.

– The compartment on the right contained the filter media and heater.

– The left side contained the submersible filter pump.


Bottom of the Filter Tank


Subject Heater Remains Position within the Filter Tank


First Evidence ExamX‐ray of the aquarium heater


Shows electrical arcing in the heater. Multiple arcs shown in the red circle.

First Evidence Exam

• Observations– A small section of the Plexiglas filter tank was broken out of the side wall of the tank.

– Examination confirmed that the piece had been broken by impact from inside the tank.

– The fracture occurred prior to the fire.

• First evidence exam was halted because the manufacturer of the aquarium heater had not been identified or notified.


Broken Plexiglas


Second Examination• Exclusively focused on the aquarium heater. • The melted plastic bio‐balls and grating surrounding the heater was removed by heating the plastic with a heat gun. – This exposed the internal electrical components and conductors.

– Obvious evidence of electrical arcing was observed on the wiring and bus bars within the heater.

– Electrical arcing was also evident at the base of the heating elements.


Electrical arcing inside the controls for the aquarium heater



Subject Heater With reconstructed glass tube placed in the filter tank in its original location.

Testing and Analysis• CASE obtained several different manufacturers and wattages of submersible aquarium heaters.

• The heaters were injected with a salt water solution meant to simulate water from a salt water aquarium.

• The heaters were then laid horizontally on the bottom of a tank, plugged into a 120 VAC power source, and turned ON.

• The current, voltage and temperature were monitored using a data‐acquisition system.


Testing and Analysis• Shortly after the heaters were energized, over‐pressurization occurred inside the heater which caused the glass test tube to “shoot” off the heater.

• The ejection of the glass test tube was violent, causing the tube to be swiftly ejected from the heater.

• The force of the test tube ejection appeared sufficient enough to cause the Plexiglas to break.


Exemplar Heater “Shoot Off” Due to electrical arcing as a result of water infiltration


Burn Testing


Burn Testing Fire Progression


Conclusion• The origin of the fire was determined to be the north wall of the

lobby area. • V‐pattern behind the aquarium indicated potential area of origin. • Presence of electrical arcing within the aquarium indicated

potential cause.• The broken hole in the acrylic filter tank was found to directly

correlate with the location of the aquarium heater.• The glass tube of the heater was found to have separated from

the electrical control body resulting in a final length equal to the available distance within the filter tank.

• Electrical arcing within the heater confirmed that the cause of the fire was the heater, and the arcing also eliminated other potential areas of origin.


PROPERTY FIRE, STRUCTURAL SAFETY, REPAIR AND REMEDIATION

Property Fire

• Assessing Structural Safety• Repair and Remediation

Damage


Repair

property and appliance fires - jensen hughes · 2015/10/13 · senior electrical engineer •b.s....

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