As It Happens

'We'll never be able to finish this project': Why identifying 9/11 victims is still so difficult

The latest identification of a 9/11 victim has been announced in New York City. The forensic scientist who leads the DNA identification team sheds light on the immense work that still remains to be done.
In this Nov. 7, 2001 file photo, workers and heavy machinery continue the cleanup and recovery effort in front of the remaining facade of 1 World Trade Center in New York. (Stephen Chernin/AP)

After nearly 16 years, the remains of a man killed at the World Trade Center during 9/11 have been identified. The news marks a small step in a long, painstaking journey to identify victims.

Since 2001, the New York City's medical examiner's office have been working with DNA fragments from Ground Zero to identify the 2,753 people killed that day. So far, the identities of 1,641 victims have been confirmed.

The identity of the latest confirmed victim has been withheld at the request of the family. But the confirmation wouldn't have been possible without the help of Mark Desire.

Mark Desire, right, with the Office of Chief Medical Examiner, talks with a forensic criminalist as he prepares to enter the bone grinding room at the Office of Chief Medical Examiner in New York. The room is central to the examination of bone DNA from those who died on Sept. 11, 2001. (Bebeto Matthews/AP)

Desire works at the city's medical examiner's office, and is head of the DNA Missing Persons Unit that oversees the World Trade Center identifications.

As It Happens guest host Rosemary Barton spoke with Desire about why identifying the victims is such a difficult process. Here is part of their conversation.

Mr. Desire, this man that was recently identified died almost 16 years ago. Why did it take so long?

The technology needed to identify his remains is much more advanced today than it was in 2001. And it took that advancement to finally, after all these years, be able to generate a DNA profile. There were almost 22,000 remains recovered from the World Trade Center attacks. And all these remains have been attempted many times in hopes of generating a DNA profile.

Fiery blasts rock the World Trade Center after being hit by two planes Sept. 11, 2001 in New York City. (Spencer Platt/Getty Images)

And we're talking about small, small pieces of DNA that you would have to uncover, right? This is tedious, exhausting work, I would think.

Yes. Some of the remains are very small, and they've been exposed to the harshest of conditions. Things that will destroy DNA such as fire, jet fuel, sunlight, water, mold, bacteria — all these things destroy DNA, and all those things are present at Ground Zero.

So what is the technique that you can use, that you didnt have 16 years ago to uncover people's DNA?

The philosophy is the same. You have bone material and this bone is the hardest of the biological materials to work with — blood and saliva, those samples are much easier. You have to break the bone down into the cellular level. The more you can break it down, the more access you'll have to the DNA. So throughout the years we've even improved that process by pulverizing the bone, creating almost a fine talc using the most modern of techniques today to create this bone powder.

Rosemary Cain, mother of firefighter George Cain, a victim of the Sept. 11, 2001, attacks, protests the decision by city officials to keep unidentified human remains of the 9/11 victims at the 9/11 Museum at the World Trade Center site. (Andrew Burton/Getty Images)

What can you tell us about this man in particular?

We'll leave it to the family of the victims to state whether or not they would like the name released. Some family members want it private. Other family members do not even want to be notified. Whatever they wish, we're going to follow that.

I think that everyone handles grief differently. For some of the [9/11] victims, we've identified over 300 pieces from a single person using DNA. So those are a lot of phone calls — going to visit the families, to tell them we've found another fragment of their loved one.

A sign to the entrance of the bone grinding room at the Office of Chief Medical Examiner in New York. Forensic scientists are still trying to match bone fragments with DNA from victims of 9/11 who have never been identified. (Bebeto Matthews/AP)

This man was the 1641st person to be positively identified out of more than 2700 people killed. How long do you think it's going to be until you've finally identified everyone?

We will never be able to finish this project. Half of the challenge for us is to generate DNA from the material recovered of the victims from Ground Zero. The other half of the challenge is getting DNA samples from family members. We need toothbrushes, razors, swabs from moms and dads, brothers and sisters. We do not have those reference samples from all the victims. So there's about a 100 victims we will never be able to identify.

This interview has been edited for length and clarity. For more on this story, listen to our full interview with Mark Desire at the link above.