Americans still worried about major terrorist incident 16 years after 9/11 attacks

A couple embraces on the Brooklyn Promenade as the Tribute in Light rises above the lower Manhattan skyline, Sept 10, 2017, in New York. The two blue pillars of light provide a visual reminder of how the Twin Towers, destroyed in the terrorist attacks of Sept 11, 2001, once stood above the city skyline. [Photo/IC]