19,915. 9,429. 10,486.
  
 These are some of the most telling numbers related to Sept. 11. They are, respectively, the number of human remains recovered from Ground Zero, the number of remains identified with one of the 2,752 victims, and the number of remains that are still unidentified to this day.

    DNA technology has basically vanquished the "unknown soldier," a staple of the war memorials of yore. It took 9/11 to revive a brutal version of that phenomenon: the "unidentified remains." They sit in trailers operated by the New York City medical examiner's office, visible off the well-trafficked FDR Drive, passed by thousands of unknowing motorists a day. They are a neglected reminder of the sheer savagery of the Sept. 11 attacks and the unfathomable human toll of that day.

    I talked to a retired fire marshal who was on morgue duty at Ground Zero in the months after the attack. He requested anonymity because he made a pledge with other rescue workers that they wouldn't talk to the press and possibly be made out as heroes when they were only doing their duty. "I never took a course in mortuary science," he says. "We just did it. Someone said: 'You guys, you guys, you guys. You're the morgue detail. OK?' 'OK.'"

    He and his colleagues saw things no one should see, a gruesome view of the worst attack on U.S. soil ever. "People don't know the horror, the real horror in this," he says. "They don't know what we saw. They don't even know most of the people are still at the medical examiner's office."

    Initially, recovery crews found mostly intact but crushed bodies. "That gave us false hope," he says. "We thought that is what people are going to look like." But those were the victims outside the building. The people trapped inside were caught in the tons of cascading steel and concrete, and were ground to bits, or to literally nothing.

    Recovery workers were grateful to find any body part, however small. "Usually in a morgue, you don't want to be busy," he says. "But when we had a slow day, it was horrible. It meant we weren't getting anyone back. We knew we had 3,000 people in there, and we needed to get them back."

    The possibility of giving a family a measure of finality by finding an identifiable remain was what made the work tolerable -- barely. "That's the only thing that kept people from jumping in the Hudson River and swimming to New Jersey," he says.

    Care was taken to honor the dictates of human dignity among the carnage. "If we found a human remain," he says, "we put it on a gurney, we covered it with a flag, and we ceremoniously carried it out." The work went on and on and on. "They were finding remains up to the point we scooped the last bit of dirt up in June 2002," he says.

    The remains were sent to the city's medical examiner's office, where a heroic effort was undertaken to identify as many of them as possible. Initially, the office thought it would only analyze remains the size of a thumb or larger, but it ended up analyzing smaller parts too. It has stretched the limits of science, attempting to tease fragile DNA clues from decomposed shards of bone.

    The identifications have slowed considerably, but one was made as recently as Aug. 31, and five total were made in August. Each is a small moral victory, a triumph of respect for individuality in the face of indiscriminate murder. All the remains are being preserved for the day when technological advances will make more identifications possible. Eventually, they will be removed from the examiner's makeshift site -- which includes a room where families can grieve and pray -- and taken to the official 9/11 memorial at Ground Zero.

    For now, a mostly unremarked memorial sits in the city's midst, three years later. 19,915. 9,429. 10,486.