NEW YORK (CBSNewYork) – In September of 2001, the medical examiner’s office made a commitment to do whatever it takes to identify all those who died in the World Trade Center attacks.

CBS2’s Jessica Moore got a rare look at how they are keeping that promise.

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“For the first time for at least as far back as I can remember, we are showing you how our bone laboratory works,” said Chief of Laboratories Timothy Kupferschmid.

The nucleus of the largest forensic investigation in the history of the country remains the 9/11 site in New York.

“This work has defined my career 17 years,” said Assistant Director Mark Desire. “It gets emotional working with families we’re very close with families and that’s very uncommon we’re trained to be impartial and unbiased but it’s different with WTC.

Desire says 22,000 body fragments were recovered from the World Trade Center, all of which were brought to the New York City DNA crime lab.

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Now 17 years later, scientists are still refining the process for identifying victims.

What once required hand grinding is now done by a machine, which uses liquid nitrogen to pulverize the bone, resulting in more easily identifiable cells.

Chemicals are then added to the bone powder to remove impurities and extract DNA, and

Desire says the lab is still trying to match DNA to about 100 still unidentified victims from 9/11.

“It’s humbling to work on a project so big but you feel honored to do this kind of work and when you can make identity even after all these years when you do id them it’s very special,” he said.

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The tireless work could one day give families the answers they’ve been so desperately searching for, and in the future, improvements could cut time down to 90 minutes.