Context of the Scene
On a Saturday afternoon in August, a tropical storm hit the southern portion of the United States of America causing the structural failure of a hydroelectric dam. The subsequent flood water rushed towards a nearby shopping mall sparking an electrical fire. The fire spread quickly and, despite warnings about the approaching fire were given, the speed of the fire prevented a large number of people from escaping the building. The time of day and week suggests that the mall will have contained a large number of people and members of the first response teams are believed to be amongst the casualties.
This setting suggests an open population of casualties which will complicate individual identifications (DePaolo, 2015). Fortunately, within the United States exists the Disaster Mortuary Operational Response Team, or DMORT, who can respond quickly and efficiently to disaster such as this (Stopford,2005; Byers, 2016). Remains can be expected to be found anywhere within the shopping mall which may have more than one story, but there may be an especially high concentration of remains clustered around exits, stairways, or even large windows as people in these sorts of situations attempt a panicked escape (Belluck and Von Zielbauer, 2018).
The reported speed of the fire indicates what is known as a turbulent fire which typically burn at temperatures ranging from 800 – 1000°C (Schmidt and Symes, 2015). Victims exposed for longer durations at these temperatures will have very few remaining identifying indicators such as facial characteristics and fingerprints and will likely be intermixed with charred building materials (Bohnert, Rost, and Pollak, 1998). Anthropologists participating in the recovery of the remains will have to be, as always, very cautious when handling human remains, however, when human bone is exposed to high temperatures, heat causes bones to dehydrate, calcinate, shrink, delaminate, and fracture (Ubelaker, D.H., 2009). The muscles, tendons, and ligaments of bodies exposed to high temperatures have been noted to shrink into what is known as a pugilistic posturing, where the body seems to curl inward in a what has incorrectly been described as a 'hiding position (Schmidt and Symes, 2015). This type of posturing will be common in a large percentage of the casualties.
Biological Identification of Individuals
Processing of the scene begins once it has been deemed safe by the necessary professionals. Bodies should then be located before the area is mapped, preferably in a grid-like structure. Bodies should then be photographed prior to excavation, in the case of remains buried in rubble, or collection by trained persons. Careful documentation of all collected specimens is paramount should legal formalities take place at a later time. Bodies should be stored in separate bags along with any artefacts which they may have been associated with. Osteological material found in no apparent association with a body should be stored in smaller, separate bags. All bags should be labelled with a unique bar code or some other tag to assist in the identification and tracking of samples with software similar to the Laboratory Information Management System (Labware.com, 2018). Upon arrival to the morgue, these bags should be CT scanned within the bags and prioritised based upon identification potential which can be based on the Crow-Glassman Scale (Glassman and Crow, 1996).
Identification using this scale increases in difficulty when moving upward in the levels of thermal alterations. Level one is made describes victims who likely died as a result of smoke inhalation and who will present only with minimal epidermal blistering and singed hair. Level one casualties are considered recognisable for identification and therefore candidates for facial recognition by family members. Level two consists of victims who are possibly recognisable and may still possess hands, feet, genitalia and ears. Casualties such as these are less ideal for facial identification, but the presence of hands may allow for fingerprint analysis and identifiable genitalia will greatly simplify the sexing of individuals. Facial recognition becomes an impossibility once passing level three, or nonrecognisable, these individuals present with a large amount of disarticulation in the skeleton, especially to the head and the extremities. The skeleton is degraded further in level four, extensive burn destruction, where the skull and extremities are extremely fragmented or even missing. The final level, cremation, much of the tissue has been burned away and only bone fragments remain.
Identification of casualties on levels one and two will begin with working closely with local and likely federal law enforcement. Public transport in the United States is fairly unpopular, which means many mall-goers are likely to have arrived via a private vehicle (Bento et al, 2005). If a vehicle is still present, it is possible that the registered owner is among the casualties. Similar methods were used in the Kaprun Cable Car Disaster to generate a preliminary list of missing persons following the event (Meyer, 2003). First responders will need to be contacted to generate a list of emergency service members who may be among the casualties and nearby hospitals should communicate a list of those who are receiving treatment or within their morgues as a result of this tragedy. A hotline will need to be implemented and popularised by national media so that friends and family members can report the missing. Law enforcement can also be utilised to distribute identification questionnaires detailing the missing person's name, ancestry, sex, age, identifiable characteristics, like tattoos or birthmarks, and medical history, such as past bone trauma or chronic diseases. Included with the questionnaire should be a DNA collection kit so as to obtain comparative materials for DNA analysis. Instructions in these packets will ask relatives to include options such as toothbrushes, shavers, hair brushes, clothes, towels, food leftovers with bite marks, used dishes, or buccal swabs from relatives (Meyer, 2003).
In the cases of levels three to five in the Crow-Glassman Scale, DNA analysis can play a crucial role in the identification of individuals. Although the bodies may be significantly burned, it may be possible to obtain cardiac blood, skeletal muscle tissue and swabs of the urinary and gallbladder. These methods were also used in the aforementioned Kaprun Cable Car Disaster and were inspired by the methods used in the Tauern Tunnel Disaster (Meyer, 2003). The near immediate collection of cardiac blood and other samples paired with local law enforcements collection of comparative material resulted in blood samples being typed and positively matched to comparative material after only 19 days and yielding an impressive 100% identification rate. The Victorian Bush Fires also reported identifiable heart, lungs and liver in many cases, despite severe burning (O'Donnell et al., 2011). These major organs may be present in many cases giving an opportunity for this type of DNA collection.
The Kaprun Cable Car case also noted that, despite many of the bodies presenting with missing extremities up to the knee and elbow, it was still possible to note the remnants of genitalia in all cases which may simplify sexing in levels three and possibly four. When genitalia are not immediately apparent, CT scans, like those used the 2009 Victorian Bush Fires (O'Donnell et al., 2011), may also prove useful in determining the sex and age of individuals. A combination of external and internal genitalia, the presence of breasts or brassiere underwire and associated artefacts such as watches, and jewelry were used to place individuals into definite, probable and possible sex categories. CT scans of the bodies were able to detect sexually-specific characteristics in many cases. This included the crura of the penis and the prostate in males and the breasts, vagina, labia, cervix, or uterus in females. It should be noted that this particular paper uses the socially-charged 'gender' interchangeably with biologically-determined 'sex' which should be avoided in the case of a forensic investigation.
Age, and perhaps stature, can also be ascertained through usage of a CT scan (Giurazza et al., 2012). In the case of the Victorian Bush Fires, age was determined by a combination of long bones growth plate presence or location, dentition and skeletal indications of of chronic diseases like osteoarthritis. For those thought to be under 20, the typical growth rates and tooth eruption can be used for a more precise age (Bassed and Hill, 2011; Bassed, 2012). Ages 20-40 can be ascribed to individuals with present growth plates, but no sign of skeletal degradation. Ages 40-60 may present with mild forms of osteoarthritis and more wide-spread occurrence of this as well as the presence of joint replacements can indicate those over the age of 60. Age estimation such as these were used in 155 of the 161 cases involved in the Victoria Bush Fires and of these they produced a 76% success rate in all cases with the lowest success rate being the 20-40 and 40-60 ages groups (O'Donnell et al., 2011).
The above-mentioned methods for mass disaster victim identification show promise in leading to the successful identification for a large number of casualties associated with this shopping mall disaster. Many of the methods described here (Meyer, 2003; O'Donnell et al., 2011) were used successfully in the severely burned remains of victims from both the Kaprun Cable Car Disaster and the 2009 Victoria Bush Fire. DNA analysis, especially when paired with aging and stature identification methods using CT scans, can help forensic teams restore the identities of those who have died so traumatically and return them to their loved ones so that they may know closure.