Today, on what would have been her husband's 54th birthday, Peggy Ogonowski will leave flowers at his empty grave in Dracut. John Ogonowski, the pilot and captain of American Airlines Flight 11, is one of more than 1,100 victims of the attacks of Sept. 11, 2001, whose remains have never been identified.
New York City's medical examiner's office has now begun notifying families that it has exhausted all efforts to identify the remains of those killed at the World Trade Center, confirming the tragic truth for the thousands of relatives who wanted something, anything, to bury.
In the 3Â½ years since the attack, out of nearly 2,800 victims, rescue workers recovered fewer than 300 whole bodies, and forensic scientists identified the remains of nearly 1,600. But families are now being told that the limits of DNA technology have been reached.
For Ogonowski, her grief is mixed with praise for the city's efforts and hope that advances in forensic science will one day make it possible to identify many of the unknown remains that have been preserved.
"Their hearts were certainly in the right place, and they did their best," she said. "They were very sensitive, caring, kind, and respectful. I think as science progresses, they'll have more opportunity. I think it's amazing they have identified as much as they have."
Forensic teams worked around the clock after the disaster to identify the dead using DNA from toothbrushes and combs supplied by the victims' families. During the monumental effort, while rescue teams cleared more than 1.5 million tons of rubble at the trade center, the coroner's office kept the remains in refrigerated trucks.
Nearly 20,000 pieces of remains were found in the ruins -- more than 6,000 small enough to fit into 5-inch test tubes. The most matched to one person exceeded 200. More than 800 victims were identified by DNA alone.
Nearly 10,000 unidentified parts have been freeze-dried and vacuum-sealed for preservation in case advances in forensic technology someday enable scientists to identify the remains. In many cases, the fierce fires, the crushing debris, and other factors prevented scientists from extracting usable DNA.
"I feel very gratified that we got as far as we did, given the quality of the DNA that we had to work with," said Robert Shaler, director of forensic biology. "We know there's still some DNA there in some of these remains . . . but we need other techniques to get at it, and when that happens we'll have someone on the job to look for new identifications."
The victims' families praised the medical examiner's office and the gentle way the staff handled the heart-rending task. The medical examiner's office said it started calling families a few weeks ago and will probably send letters by next month.
"We really felt they did everything they could," said Diane Horning, whose 26-year-old son Matthew was killed.
Last year, Bill Doyle of Staten Island purchased a burial plot in hopes that the remains of his son, Joseph, would be identified. "We bought the burial plot hoping today never came," said Doyle, a leader among survivors who spent yesterday calming family members who were told the medical examiner's office could not identify their loved one's remains. "I've gotten comments from families all day long, like one woman who said, 'What happens to my husband now? Does he turn to dust?' "
Mary Fetchet of New Canaan, Conn., founder of Voices of Sept. 11, has been encouraging families to expect a call from the medical examiner's office. For the past couple of weeks, she has been getting calls from people who have already been contacted. After the attacks, many families received a call from the medical examiner's office each time a portion of their relative's remains was discovered. Fetchet, who lost her 24-year-old son, Brad, received four calls, starting in 2001. The process was so painful for families that many opted not to receive any calls until the medical examiner's office finished its work.
Some realized their loved ones' remains would never be found.
Eric LaBorie, whose wife, Kathryn, was a flight attendant on one of the jets that crashed into the trade center, said she was working in the first-class cabin and was probably at the front of the plane.
"With the impact and the jet fuel, I just kind of knew that she had vanished into the air," said LaBorie, who lives in Providence. "I would have been really surprised if they did call me and tell me they found something."
Not having a grave and other rites of mourning was frustrating, he said. He has returned to the park in Bermuda where they were married and has thought of putting a bench there in her memory.
Like so many milestones since Sept. 11, the end of the medical examiner's work is "a message to some of us, that we need to remember our family members for who they were when their bodies were here in full, and live our lives knowing that," said Robert Fazio, whose father Ronald was killed in the attacks. A mangled credit card was the only trace of Ronald Fazio recovered.
Globe staff reporter Tatsha Robertson contributed to this report. Material from the Associated Press was also used.