"To all those who responded with so much courage...it is an honor for us to join in your memories, to recall and reflect but above all to reaffirm the true spirit of 9/11: love, compassion, sacrifice and to enshrine it in the heart of our nation forever," Obama said to the victims' families. "All who come here will find it to be a profound and moving experience."
The new museum tells the stories of the nearly 3,000 people killed when two planes struck the twin towers. Occupying 110,000 square feet of the 16 acre site, the museum has more than 10,000 artifacts, 20,000 still images, and 500 hours of video and film.
The president introduced Alison Crowther, mother of Welles Crowther, who died on 9/11 while trying to evacuate his coworkers from the south tower while wearing a red bandanna. Obama then introduced Ling Young, one of the many saved by Crowther.
"For us he lives on in the memory of the people he helped," said Crowther. "Welles believed we are all connected as one human family...This is life's most precious meaning. It is our greatest hope that when people come here and see Welles' red bandanna, they will remember how people helped each other that day, and we hope they will be inspired to do the same in ways both big and small. This is the true legacy of September 11."
"We will never understand why one person escaped and another didn't...how random it all seemed," said Giuliani, who served as mayor during the time of the attacks. The museum, he said, affirms "that we can absolutely affect each other's lives by what we do at a time of crisis."
It was intended to open on the anniversary of the attacks, but construction delays and rising costs slowed progress. The museum stands next to the one World Trade Center, standing at 1,776 feet, making it the tallest in the nation. The office building is expected to open later this year.
Following Thursday's dedication, the museum will be open around the clock for free visits offered to the victim's families, survivors, first responders, and Lower Manhattan residents. It will be open to the public on May 21 with general admission fees set at $24, but reservations for that day are already sold out.
Notable deaths of 2014 [PHOTOS]