This DNA Tech Offers Hope for Identifying September 11 Victims

Twenty-five years after the September 11 attacks, advances in genetic sequencing are giving investigators new ways to identify victims whose remains have remained unidentified since the World Trade Center towers collapsed.

New York City’s Office of Chief Medical Examiner last month announced the identification of the 1,654th person killed at the World Trade Center, using a relatively new forensic technique known as forensic investigative genetic genealogy, or FIGG.

The technology combines whole-genome sequencing with genetic genealogy to search for relatives of unidentified victims, including relatives who may be considerably more distant than those detectable through conventional DNA matching.

“There is real promise in using this approach,” said Angela Soler, director of forensic anthropology in the city’s medical examiner office. “There’s hope for more families to receive answers, and hopefully we’ll be able to test more remains in the future using this technology as well.”

The identification effort illustrates how forensic DNA technology has evolved since the attacks. Investigators initially relied heavily on fingerprints and dental records. As those methods became less useful for severely damaged or fragmented remains, DNA analysis became increasingly important.

Advances in sequencing and DNA extraction have allowed investigators to return to remains that previously produced insufficient or unusable genetic information and test them again using newer methods.

“That’s why all these years down the road, we’re still getting new identifications, because we’re just continuing to retest and retry with every new technology that becomes available,” Soler said.

The medical examiner’s office says DNA technology has contributed to the identification of 1,495 victims since the attacks, either on its own or alongside other identification methods.

Of the 2,753 people killed at the World Trade Center, about 60% have been identified, leaving more than 1,000 victims whose remains have yet to be matched to a name.

The challenge is unusually difficult because the attacks subjected human remains to intense fires, structural collapse and other forms of damage. Investigators often recovered only small fragments, reducing the amount and quality of DNA available for analysis.

The sheer scale of the World Trade Center disaster also distinguishes it from the other major crash sites on Sept. 11. Five of the 184 people killed at the Pentagon were never identified, while all 40 passengers and crew members aboard United Airlines Flight 93 were identified using DNA, dental records and fingerprints.

The new technology is particularly significant because FIGG does not require investigators to find a close relative of the victim in a conventional DNA database.

Soler said the approach uses whole-genome sequencing, which reads an individual’s genetic code in much greater detail and can enable investigators to identify potential matches among more distant relatives.

Once those distant relationships are identified, investigators can work backward through family trees. The New York Police Department then helps locate closer relatives who can provide stronger evidence for confirming an identity.

The approach effectively expands the pool of people who can help investigators establish who an unidentified victim was.

That could prove important as conventional identification methods reach their limits. Many of the remains recovered after the attacks are highly fragmented, while some contain little recoverable DNA. But investigators have preserved remains specifically so they can be subjected to improved testing as science advances.

Last year, the city announced the identification of three more victims through DNA testing, 24 years after the attacks: Ryan Fitzgerald, a 26-year-old currency trader; Barbara Keating, 72, who was aboard American Airlines Flight 11; and a woman whose family chose not to make her identity public.

The continuing identifications also highlight an unusual feature of forensic genetics: evidence that failed to produce an answer decades ago can become useful as sequencing technology improves.

For Juliette Scauso, whose father Dennis was a firefighter with the New York Fire Department’s hazardous-materials unit, the issue is deeply personal.

Scauso was four when her father died. His damaged firefighter helmet, bearing his badge number, was the only physical trace of him that her family recovered.

“I’ve spent essentially my entire life knowing my father died, and learning to live with the fact that we never recovered him,” said Scauso, who was four when he died.

Her father had not been scheduled to work on Sept. 11 but had switched shifts for overtime pay. The family was told he was likely inside the South Tower when it collapsed.

Scauso said the circumstances of the response also complicated identification because firefighters changed shifts and some stayed beyond their scheduled assignments, sometimes using equipment belonging to colleagues.

But even as the technology improves, identification is not universally welcomed by families.

The medical examiner’s office continues to receive weekly calls from relatives seeking information about victims whose remains have never been identified. Some families want recovered remains placed in a repository beneath the World Trade Center site, while others prefer not to receive notification if an identification is made.

Scauso falls into the latter group. “At this point, an identification wouldn’t change the reality of his death. It wouldn’t give me back my father, and I don’t necessarily want to reopen something that has become part of the way I’ve learned to live and grieve,” she said. “Especially 25 years later, it’s going to open up the wounds again.”

Still, she said the technology matters. For Soler, identifications can provide a definitive answer to families who have spent decades knowing that a relative died but lacking forensic confirmation.

“It’s confirmation of something that they always knew to be true – they knew their loved one died on 9/11, but I think for many families, there’s still that question in the back of their mind until the remains are formally identified,” Soler said.

“Maybe they’re reliving it a little bit more now, having this new identification. But at the same time, it closes one chapter of their journey after 9/11,” she added.

The medical examiner’s office has acknowledged that it may never identify every victim. In some cases, there may simply be too little biological material remaining to establish an identity.

But advances in sequencing, extraction and genetic genealogy mean that investigators are not necessarily limited by the capabilities of the technology available in the years immediately after the attacks.

“As long as there’s families looking for answers, we’ll continue searching for them,” she said.

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