Although 17 years have gone by since the 9/11 terrorist attack on the United Sates, some 1,000 victims have still not been identified.
Medical advances can be crucial, however, and DNA tests being carried out by a team of forensic experts may help to reveal the identity of victims who have still not been identified.
From genetic material collected from Ground Zero, the place where the two World Trade Centre towers had stood, experts have announced the use of a new technique through which bone fragments are taken to a room contining liquid nitrogen, where the bones can be ground into very fine dust.
The more the bones are ground, the more possibility that DNA can be extracted in an attempt to identify the persons who lost their lives in the worst terrorist attack ever carried out in the United States.
Whilst this discovery is being hailed as the biggest in US forensic history, this development has re-opened the wounds for the families of victims who were buried at Fresh Kills Landfill on Staten Island without having been identified.
On 11 September the terrorist group Al Qaeda carried out a number of coordinated attacks on strategic sites in the US through airplanes hijacked by terrorists, and in which just under 3,000 persons lost their lives.
Watch how these new DNA tests are being carried out in order to identify the victims, as well as the views of OCME, the biggest forensic laboratory in the US.