An artist's image of the wall that will separate the public from the repository where unidentified remains will be kept at the National September 11 Memorial Museum in Manhattan. 911memorial.org hide caption

itoggle caption 911memorial.org

A woman looks out at One World Trade Center from inside the 9/11 Empty Sky memorial at Liberty State Park in Jersey City, N.J., on Wednesday. Americans commemorated the 12th anniversary of the Sept. 11 attacks with solemn ceremonies and pledges to not forget the nearly 3,000 people killed. Gary Hershorn/Reuters/Landov hide caption

itoggle caption Gary Hershorn/Reuters/Landov