President Obama commemorated victims of the Sept. 11 attacks at the recently completed museum and memorial in a service Thursday.
"Here we tell their story so that generations yet unborn will never forget. Of coworkers who led others to safety, of passengers who stormed the cockpit, our men and women in uniform who rushed into an inferno, our first responders who charged up those stairs, a generation of service members, our 9/11 generation who have served with honor in more than a decade of war," the president said.
Because of their sacrifices, and the work of those who helped create the museum, the president said, the United States is "a nation that stands tall and united and unafraid because no act of terror can match the strength or the character of our country."
"Nothing can ever break us," he said. "Nothing can change who we are as Americans."
Before his speech, the president and first lady Michelle Obama viewed the museum with former President Bill Clinton and former Secretary of State Hillary Clinton, as well as former New York Mayor Michael Bloomberg and his wife, Diana Taylor.
Mr. Obama said the museum will be a "profound and moving experience" for those who visit it.
The president opened and closed his remarks with the story of 24-year-old Welles Crowther who is credited with helping to evacuate and save several people from the South Tower. Survivors recalled the red bandanna he had worn around his nose and mouth to protect from the smoke, which allowed Crowther's mother to identify her son in a news article months after the attack. He had carried a red bandanna since he was a child.
One of Crowther's bandannas is among the artifacts on display in the new museum. His mother, Allison Crowther, and a woman he had saved, Ling Young, spoke briefly after the president.
"Those we lost live on in us, in the families who love them still, in the friends who remember them always, and in a nation that will honor them now and forever," the president said.