FIRE DEATHS The Role of the Forensic Pathologist Marie Cassidy State Pathologist

FIRE DEATHS Accidental – children, elderly, alcohol related, smokers Suicide – uncommon, Asian females Crime – arson, concealment of homicide, insurance fraud

Aims of the Autopsy Establish Positive Identity Was the Deceased Alive at the Time of the Fire? The Cause of Death Any Contributory Factors (eg natural disease,alcohol,drugs) preventing escape Time of death

IDENTIFICATION Visual (including scars,tatoos etc.) Circumstantial (jewellery,documents,spectacles,dentures) Radiographs (cranial sinuses,bony abnormalities,surgical implants) Dental DNA

CAUSE OF DEATH Neurogenic Shock - pain Thermal Injury (hypovolaemia, shock, acute renal failure) Inhalation of Smoke and Fire Gases – most common - asphyxia Delayed Death Natural disease - ? Fire caused death Injuries - ? Fire caused death Homicide - ? Fire caused death

Inhalation of Smoke and Fire Gases Thermal injury to airway (laryngeal oedema, bronchospasm) Carbon monoxide (200 x affinity for Hb) Cyanide Acrolein (wood and petroleum products) Hydrochloric acid (plastics, furnishings) Toluene Diisocyanate (from polyurethane) Nitrogen Dioxide (automobiles, agricultural waste)

Types of Burns Flame Burns (including flash burns) Contact Burns (eg hot iron) Radiant Burns Scalding Burns Microwave Burns Chemical Burns (generally,alkaline more severe than acid)

BURN SEVERITY 1 st Degree----erythema,oedema,pain 2 nd Degree----blisters,pain 3 rd Degree----full thickness,sensation lost 4 th Degree----charring(incineration) Alternative: Partial thickness Full thickness

Extent and Outcome of Burns Charts “Rule of Nines” Percentage of Total Body Surface Area 100% burns -prognosis poor >70% burns -likely to be fatal

Probability of Survival Age of Individual Percentage of Total Body Surface Area Children can survive extensive burns Elderly may succumb after minor burns AGE + PERCENTAGE < 100

BURNS----- antemortem v. postmortem Differentiation of antemortem burns and postmortem burns is usually IMPOSSIBLE Gross- red flare, blistering, parchmenting Microscopic – vital reaction HEAT FRACTURES - SKULL FRACTURES (recent research to assist identification of antemortem fractures)

CHARRED BODIES Post-mortem examination is ALWAYS worthwhile Internal organs often well-preserved Splits in skin and muscle (run parallel) Pugilistic Attitude (occurs as body cools) Parts of Body may be Absent – check scene X-Rays Heat Epidural (an artifact) Airways (soot) Carbon Monoxide

Delayed Death Shock, Renal failure Adult Respiratory Distress Syndrome Sepsis (burns or pneumonia) Pulmonary Embolism

Escape ? Trapped by fire Unable to see way out Immobilised by fear Intoxicated by alcohol or drugs Illness or natural disease Injuries – pre or during fire

Toxicology Carbon monoxide levels Cyanide Alcohol Drugs