. >> on 9/11, diane horning lost her 26-year-old son, matthew, who was working on the 95th floor of thenorth tower. she and some other families have fought hard to get the remains moved to a common burial site. >> we just want what every person in this country gets, which is a decent, respectful burial, which is what we gave osama bin laden. i'm not angry that he had a burial with rites and rituals. i think that shows a common decency, and we want the same. >> despite intense efforts to find all the remains, the fact is of the 2,753 murdered at the world trade center, the remains of more than 40% have not been identified. when the 9/11 memorial opens september 11, there will be no common burial site for the remains. thousands of unidentified bone and body fragments will be placed near the museum behind a wall with an inscription from virgil reading, "no day shall erase you from the memory of time." there scientists will continue trying to identify the remains. james young is an expert on memorials. >> oncthe families know that the remains are right nearby, for them the memorial experien