A New York City firefighter looks at the last column recovered at the World Trade Center site at the dedication ceremony for the National 9/11 Memorial Museum on Thursday, May 15, 2014 in New York. The museum memorializes the September 11 attacks on the World Trade Center in New York. (AP Photo/John Angelillo, Pool)
Two people embrace while gathered on the plaza of the National September 11 Memorial to watch the telecast of the dedication ceremony at the National September 11 Memorial Museum in New York on Thursday, May 15, 2014. (AP Photo/Justin Lane, Pool)
A woman in the audience dries a tear during the dedication ceremony in Foundation Hall, of the National September 11 Memorial Museum, in New York, Thursday, May 15, 2014. (AP Photo/Richard Drew, Pool)