The National September 11 Memorial Plaza–a solemn space where visitors can remember and honor the lives lost during 2001 and 1993 terrorist attacks–will open on Sunday at the World Trade Center site. The September 11 Museum will open on the site next year. Behind the Plaza, 1 World Trade Center continues to rise. With tower steel above the 81st floor and facade installation at 56 floors, it has already changed the Manhattan skyline. [Photo by Brian DiFeo]
