Analysis of 101 Vehicle Fire Fatalities

Abstract

Vehicle fire fatalities encompass both fire and traffic investigations important for the forensic pathologist. Previous studies have demonstrated the challenges in victim identification, determining cause and manner of death, evaluating the role of collision dynamics, and estimating the excess burden of deaths due to post-collision fire. To address these challenges, the present study analyzed 101 vehicle fire fatalities representing 85 accidents, six suicides, four homicides, two natural deaths and four deaths of undetermined manner. Deliberately set fires in homicides, suicides, and suspicious deaths caused nine deaths. Nonaccidental deaths were twice as common in parked vehicles. Of 78 collision fatalities, 46 were occupants of cars, 47 were drivers, and 48 died in collisions involving fixed objects or non-impact rollovers. Occupants of heavy trucks and collisions with light trucks and SUVs had the highest per-collision fatality rates. Frontal and rollover collisions claimed most lives, and rear collisions had the highest fatality rate. Carboxyhemoglobin (COHb) levels were highest in parked cars wherein toxic inhalation occurred prior to fire. In post-collision fires, COHb ranged no higher than 31% saturation and were much lower than in house fires. Potentially survivable blunt force injuries (BFI) and no BFI were present in more than half of charred bodies of post-collision fires. Evidence of inhalation of combustion products correlated imperfectly with severity of BFI, and airway soot deposition was a more sensitive indicator of post-collision viability than COHb. Between 13% and 59% of collision fatalities were due to post-collision fire and not BFI.