Editor's note: This story contains a frank discussion of death and human remains. It may not be suitable for all readers.
As firefighters work on expanding containment of the deadly wildfires in Northern California, recovery efforts are underway even as the death toll climbed to 42 Wednesday. The mayor of Santa Rosa today asked the state of California for help in cleaning up the city, and part of that effort will involve identifying the remains of people who died in the fire.
ASU Now talked to forensic anthropologist Anthony Falsetti, a professor of practice at Arizona State University's School of Mathematical and Natural Sciences, about how experts can — and can't — identify victims of a blaze. (Falsetti also encourages those with missing loved ones in Arizona to attend Saturday's Missing in Arizona Day; event details at the end of this story.)
Question: Forty-two people died in the Northern California fires. The Sonoma County sheriff said earlier this week some of the remains being found are nothing but ashes and bones. Is it possible to identify remains like that?
Answer: The loss of life is terrible, and our hearts go out to the loved ones of the missing and presumed dead. Simply stated, yes it is possible to locate, recover and identify burned human bones from a fire scene. Forensic scientists who are trained to distinguish human bone from other items found in the environment are referred to as forensic anthropologists. A forensic anthropologist can identify human bone from non-human materials in the field and determine what bone is it, and depending on certain anatomical characteristics or features whether that bone belongs to a male or female and perhaps how old the person was at the time of their death.
Q: What are the chief challenges in forensics where fire is involved?
A: The greatest challenge presented by fire is the destruction of biological tissue or evidence of identity. Forensic anthropologists, pathologists and odontologists (forensic dentists) perform the task of determining who, or the identity of individuals in the forensic setting.
Without an intact body, the challenge of positively identifying an individual is difficult. Without useable DNA, intact dental evidence or complete bones, the challenge becomes more difficult since features become destroyed or damaged. In the instance of fire or thermal-related deaths, this challenge becomes more complex due to the destruction of identifying features of the person. Fire destroys the most obvious individuating characteristics we all have such as hair color, tattoos, dental traits, etc.
Q: Are there circumstances where it’s impossible to identify remains?
A: Yes, there are scenarios where it is impossible to positively human remains to a specific individual. This could be the result of their not being any existing antemortem records such as medical or dental records existing for the living person; thus, nothing to compare the postmortem information against. Or the remains could be so damaged or compromised by heat that it’s impossible to extract DNA or the teeth are too fragmentary for reconstruction that good or reliable postmortem data collection is impossible. In my experience, it is a rare situation where a forensic anthropologist is unable to reconstruct some living characteristics from bone, even those that are burned.
Q: One would imagine if the only remains were ashes in a home, investigators might nail down the identity by going over who was likely to be in the home. How would a forensic investigator identify multiple remains found in one building, as in the Oakland Ghost Ship warehouse fire last year?
A: The Oakland Ghost Ship warehouse presents a difficult scenario since it was a converted structure never designed to house a party or be operated as a dance club, nor had it passed the appropriate fire marshal inspections to operate legally. Thus, there was no fire-suppression equipment installed, allowing the fire to travel unchecked throughout the structure.
Nonetheless, a forensic investigator would be able to sort out the victims by age, sex and possibly by ancestry using scientifically validated methods to create a postmortem profile of the deceased. These profiles could then be used to generate unidentified-persons lists and made available to be compared to those people reported missing. Dental and other morphological characteristics such as healed fractures or other anomalies could be compared to medical records of the missing once possible matches are identified. This is a process referred to as reconciliation of postmortem and antemortem records. If, during this record comparison, no contra indicators are discovered, then a presumed ID can be proposed for final evaluation or comparison of dental, medical or DNA reports.
Missing in Arizona Day
What: An event dedicated to connecting people with the resources to find their long-term missing loved ones. Law enforcement will take reports and gather information and identifiers (DNA, medical records, fingerprints, photographs, etc.) from families of missing persons. Families are encouraged to bring medical and dental records of their missing loved ones. The event is free and open to the public.
When: 10 a.m. to 4 p.m. Saturday, Oct. 21. A support group will be held from noon-2 p.m. for family members of a missing loved one; pre-registration required. There will be a candle-lighting ceremony at 3 p.m.
Where: ASU's West campus (La Sala ballrooms A, B and C), 4701 W. Thunderbird Road, Glendale.
Top photo: The Copernicus Sentinel-3A satellite captured this image of smoke from wildfires in California on Oct. 9. Wildfires broke out in parts of the state on Oct. 8 around Napa Valley, and the smoke was spread by strong northeasterly winds. By European Space Agency - http://www.esa.int/spaceinimages/Images/2017/10/California_fires, CC BY-SA 3.0-igo, https://commons.wikimedia.org/w/index.php?curid=63312825