NEW YORK (CBSNewYork/AP)– Cardinal Timothy Dolan presided over a solemn memorial service at St. Patrick’s Cathedral in New York City for the 343 firefighters who died 15 years ago in the Sept. 11 attacks.

Attorney General Loretta Lynch was at the service representing President Barack Obama. Mayor Bill de Blasio also spoke at the service.

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He said every New Yorker suffered on 9/11, but none more than the members of the fire department. He noted the firefighters killed ranged in age from 22 to 71.

The massive Roman Catholic cathedral was filled to capacity with city dignitaries, firefighters and families of those killed.

(Credit: WCBS 880/Stephanie Colombini.)

(Credit: WCBS 880/Stephanie Colombini.)

“To stand before the men and women of the FDNY is a moving experience always. To stand before the family members of those we lost is a humbling experience always. And to the family members, so many of whom I have met and heard their stories from over the years, I can only imagine what you feel today,” de Blasio said. “I know so many of you have told me the pain does not go away. This time of year is a tough time of year. I also know you tell me the stories of the joy that your loved ones gave you when they were here with us, the pride they gave you, the way everyone looked up to them because they served in the FDNY. And we carry those good and warm memories every day as well.”

A procession into the cathedral featured a banner with the number 343, followed by firefighters carrying American flags representing every member of the department killed that day, WCBS 880’s Stephanie Colombini reported. 

Meanwhile, the 9/11 memorial reflecting pool brings people from all over the world to pay tribute, CBS2’s Magdalena reported.

Traveling from Newfoundland, one group of tourists feel a special connection here.

“We booked our hotel a year ago for this. We just wanted to be here so badly. For the 15th anniversary,” Janice Young said.

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Fifteen years ago, their small town of Gander was flooded with thousands of air travelers, all grounded when the terror attacks happened, without a place to go.

“If you need to have a shower, we took you to the house, or a meal, we just took care of people, that’s what we did,” Joe Tumilty said.

Glenn Nerbak is a high school teacher in Maine who lost a friend in the North Tower. His mission is to teach a new generation about the day that changed our lives as Americans.

“Because they were one or two years old at that time they don’t fully understand what happened on that day and why things are what they are now. I’m trying to help them understand that,” Nerbak said.

The memorials are a testament to resilience, proving terror has not won and that those killed are ever-present in the minds of survivors, family and friends, 15 years later.

“I know that my dad’s memory, other people’s family, their kids, their sons, will never be forgotten,” Tommy Merriweather III said.

The words spoken at the 10th anniversary mass ring true today.

“Out of the depths of this tragedy we were able to rebuild the greatest fire department in the world. We were able to succeed because we had the memory of the 343 with us at every moment,” Former FDNY Commissioner Salvatore Cassano said.

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President Obama has officially dedicated this weekend as national days of prayer and remembrance.