Unknown remains of World Trade Centre dead to be interred on site

Unidentified body parts from victims of the 11 September attack in New York are to be placed inside a future memorial at the twin towers site in the hope that in years to come advances in science will finally allow medical examiners to put names to them.

Almost two years after two hijacked jets demolished the towers of the World Trade Centre, the remains of almost half of the 2,792 people killed in the attack have still not been identified, and the limits of DNA technology mean there is currently little chance any new identifications can be made.

Examiners have said they still have some 12,000 body parts, ranging from mere bone fragments to remains weighing up to 100lb, that have not been definitively tied to known victims. Each will be individually placed in a vacuum-sealed pouch and stored inside the memorial.

The decision has been welcomed by most of the families whose loved ones have not been identified. It will at least allow them to visit a single spot in the knowledge that the ones they lost are inside among the untagged remains. There are 1,271 victims whose bodies have not been identified.

Shiya Ribowsky, the deputy director for the investigation into all remains kept at the New York medical examiner's office, said: "This is a very respectful and practical way for caring for these remains in perpetuity. Our job is to inter them and, if technology changes in the future, and we have a better chance to identify them, we will have to keep and preserve the remains in such a way that we can use that new technology." All the parts will be dried and sealed in bags, so will not need refrigeration.

The second anniversary of the attack will be marked by a ceremony at the site at which 200 children of those who perished will recite all of their names. In addition, the twin beams of light that shone from close to ground zero in the weeks after the attack to evoke the missing towers will be switched back on. Officials said the lights would be turned on for one evening on every anniversary of the tragedy.

A total of 19,936 body parts were recovered from the site after the disaster. Families of victims were invited to aid the investigation by giving items such as hair from combs to help examiners to make DNA matches with their loved ones.

Such was the force of the collapse of the two buildings and the heat of the fires, though, that in many cases the DNA of victims was far too severely damaged to allow for matches to be made.