Sept 11 Memorial Waterfalls

Architect Michael Arad visits a mock-up waterfall he designed for World Trade Center Memorial, Friday, Jan. 22, 2010, at the Brooklyn Navy Yard in New York. The 30-foot waterfalls will cascade down the sides of the footprints of the destroyed World Trade Center towers, forming reflecting pools surrounded by the terrorist attack victims' names. (AP Photo/Mark Lennihan)