NEW YORK, NY - DECEMBER 09:  Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge, lay a wreath at one of the reflecting pools at the National September 11 Memorial and Museum on December 9, 2014 in New York City. The couple, who are traveling without their 16-month-old son Prince George, are on a three-day US east coast visit. This is the Duke and Duchess's first visit to New York City, and the Duke's first trip to the nation's capital where he met with U.S. President Barack Obama.  (Photo by Spencer Platt/Getty Images)