Pope Francis met with the families of the victims of 9/11 at the Ground Zero memorial in New York on Friday, kicking off a tour that brought him to a school in Harlem, Central Park, and finally, Madison Square Garden.
The pope also met with Mayor Bill de Blasio and Gov. Andrew Cuomo.
The pope paid his respects at the 9/11 Memorial before leading a Multi-religious Meeting for Peace inside the National September 11 Memorial & Museum.
The pope paid tribute to the victims and heroes of 9/11 saying he was "moved" by being at the place where "thousands of lives were taken in a senseless act of violence and destruction."
"You can feel the pain here," he said. "It's palpable."
The pope said that when he met the families of the first responders who sacrificed their lives to save others during the attack, "I was able to see destruction is never impersonal, never abstract." He said, "destruction has a face, it has names."
"The family members show us the face of pain; pain that leaves us speechless but that screams to heaven."
But he said the pain also showed the power of love and remembrance of the loved ones lost in the attack.
"These names are written here on the grounds of the towers so that we can see them and we can touch them. We can never forget them," Pope Francis said.
The inter-faith prayer service was attended by members from the Muslim, Jewish, Jain, Christian, Sikh, Buddhist and Hindu communities at the Ground Zero memorial.
An imam and rabbi from New York paid their respects the victims of 9/11 and the first responders and spoke about how their respective religions promoted peace and unity.
Pope Francis then read out a Prayer of Remembrance for the victims of 9/11, calling them "the heroic first-responders: our fire fighters, police officers, emergency service workers, and Port Authority personnel, along with all the innocent men and women who were victims of this tragedy simply because their work or service brought them here on September 11, 2001."
Local representatives of the world religions then presented meditations from their respective traditions.
The service followed the pope's speech at the United Nations General Assembly where he appealed for an end to the religious and cultural persecution of Christians and other religious groups.
From there, the pope made his way through Central Park, were large crowds of supporters, fans and followers gathered to get a glimpse.
Some waited for hours in large lines Friday so they could line up along the pontiff's route in the park.
According to the Associated Press, 80,000 free tickets were given to those wanting to see Francis along the procession route.
Francis then made his way to Madison Square Garden, where he celebrated Mass.
The busy day will be the last for the pope in New York. Saturday morning, he will make his way to Philadelphia as part of his historic U.S. trip.