The office of New York City's medical examiner says it is stopping its efforts to identify victims of the September 11, 2001 attack on the World Trade Center. Forensic specialists say they have no way of identifying remains for 1,161 of the 2,749 victims.

The medical examiner says all means available have been exhausted in the effort to match 9,700 fragments of bone and tissue to the more than 1,100 victims for whom no identification has been found. The last victim was identified on January 12.

It is a sad day for families who had hoped for at least a tiny fragment of their loved ones to bury. Bill Doyle lost his son Joseph, who worked at a stock brokerage firm on one of the highest floors of the World Trade Center. After more than three years, he says the announcement was expected, given the limits of technology.

"Although their technology has gotten so much better because of 9/11, and they did make additional identifications, now at the moment they have hit a roadblock," he said.

The Medical Examiner's office is contacting victims' families this week, officially calling an end to the effort. But the letter being sent to the families indicates the office will reopen the search if new scientific methods become available. Bill Doyle is optimistic that he will one day be able to bury his son's remains.

"In the future, I think the medical examiner, they are not going to give up," he said. "They are never going to give up. There will be better technology and, hopefully, they will identify something of Joey's."