Under tight security, Dr. Bradley Adams leads the delicate, renewed search at Ground Zero.
"You don't just want to go in there and start ripping things out haphazardly," Adams says.
Adams is a former military POW-MIA investigator who says that so far, more than 1,000 remains have been found, some accidentally by workers on a nearby rooftop last summer, and in a manhole under a roadway more recently.
Now, excavation reaches into several zones, and some 700 locations around the site.
"It's critical it's done right, and that it's monitored, and we never have to come back and do it again," Adams says.
The remains are sent to Virginia, where Bode Technology gave NBC News a rare look at its stepped-up efforts to help identify 9/11 victims.
With improved DNA technology, experts like Lisa Ricci retest thousands of remains — some as tiny as a finger nail.
"We're very optimistic for the outcome," Ricci says. "We've been having great success so far."
DNA material is liquefied, enhanced — the final result, just a few drops.
It does not mean that everyone will be identified, but it does mean more people will be identified than was possible before.
Hundreds of samples already have been sent back to New York, where experts try to make identifications by matching DNA provided by relatives. However, during the past year or so the remains of only three victims have been identified.
Officials have promised "new identifications will be forthcoming."
"I want something," says Roseanna Stabile, who lost her husband, Robert. "So long as they keep finding, I'll keep hoping."
She wants more than a monument to mark his life.
"Just for my own personal feeling, and I just need to have him back with us," she says.
The new search could last all year. And while DNA research advances, Stabile patiently waits.