NEW YORK, NY - AUGUST 17: A vendor sells September 11 merchandise near One World Trade Center or the "Freedom Tower" in lower Manhattan on August 17, 2016 in New York City. As the nation prepares to commemorate the 15 year anniversary of the September 11 terrorist attcks in lower Manhattan, New York City finds itself a city forever changed by the events of that day. The presence of security on the street is a daily reality for the millions of residents and tourists who filter through the city. Lower Manhattan, previously a gritty neighborhood dominated by the financial industry, has become one of Manhattan's top tourist destinations with memorials to the victims, shopping malls and historical landmarks. Over 3,000 people were killed during the attacks in New York City and Washington, D.C. (Photo by Spencer Platt/Getty Images)