About 2,977 American citizens were killed in the Sept. 11, 2001 attacks — and 1,100 of them have yet to be identified.

The tragedy sparked one of the most thorough forensic investigations in American history, with the continuous discovery of remains in the ground zero area, according to an Associated Press article published Wednesday. A decade later, the hunt remains active after an appeal to the Supreme Court from hopeful relatives of victims.

Remains from the 9/11 attacks have been especially difficult to uncover. Many were fragmented, so that only small pieces of bone were found, while others were mixed in with the heaps of debris left from the buildings, requiring months of sorting and sifting, said Michael Sponsler, director of forensic and national security sciences at Syracuse University.

The process of transporting trucks and workers to the site for recovery efforts may have led to covering up many remains that will later need to be excavated as well, Sponsler said. Some remains had been found blocks away from where the World Trade Center stood, so it’s been a difficult process, Sponsler said.

Recovering remains from where Flight 93 crashed in Shanksville, Pa., was easier in comparison, Sponsler said. Whereas 59 percent of the victims from the World Trade Center have been identified, all victims from Flight 93 have been identified, Sponsler said.

The time and money devoted to the effort exceeded that of any other disaster, Sponsler said. The New York City setting contributed to the recovery complications and also required the recovery process be as thorough as possible to avoid public outcry, Sponsler said. The recovery process was also done this way to prevent future construction workers or landscapers from finding remains and so businesses would not be forced to close due to a future excavation, he said.

‘While the goal in the recovery was identification of 100 percent of the victims, the goal was not achievable in this case,’ he said. ‘Were the knowledge gained from the operation available at the start, would this have led to 100 percent identification? Almost certainly not.’

Often times when a tragic event leaves a victim’s body completely destroyed, traditional means of identification such as fingerprinting, dental records, and radiology cannot be applied, said Kevin Sweder, professor of forensics and national security sciences at SU. Sweder said even DNA from small bits of human remains, as in the case of 9/11, isn’t suitable enough for analysis.

‘Several events occurred during the World Trade Center attack that might destroy DNA evidence,’ he said. ‘Initial impact and burning jet fuel, collapse of the World Trade Center towers and high temperatures in the resulting rubble.’

The process for DNA identification usually includes taking a biological sample of a victim from before their death, such as a toothbrush or a hairbrush, and comparing it to a particular DNA sequence, Sweder said. When DNA is too degraded for analysis, a source of DNA from the mitochondria can be analyzed instead, but could only establish kinship rather than an individual’s identity. Such processes could help identify some remains, but not all, Sweder said.

‘It may be that further identification of victims will require development of new technologies that can use very small amounts of material or can work on very degraded material,’ he said.

Colleen Holland, a junior sport and human dynamics major, said she isn’t surprised by the current number of unidentified remains from the attack.

‘I kind of expect it, there’s still remains from World War I where we don’t know who anyone is, they’re just lost soldiers,’ Holland said. ‘Countries aren’t able to claim them, but everyone still pays their respect.’

meltagou@syr.edu

Published on September 11, 2011 at 12:00 pm

Contact Marwa: meltagou@syr.edu | @marwaeltagouri