14 NYPD ESU officers honored at 9/11 memorial wall rededication. Here's their story of heroism.

A quarter century after the Sept. 11, 2001, terror attacks, the NYPD is making sure the heroes that ran toward the danger are never forgotten.

Several members of the Emergency Service Unit were honored Tuesday with a newly rededicated memorial wall at Floyd Bennett Field in Brooklyn.

NYPD Commissioner Jessica Tisch said more than half of the NYPD officers killed on 9/11 were members of the ESU.

"No single day exemplifies the bravery, the selflessness, the heroism, of this unit more profoundly than Sept. 11, 2001," Tisch said. "ESU officers were the tip of the NYPD spear. They fought to get as many people [as possible] out of buildings."

"This wall is not merely wood, pictures and name plates. It is a permanent reminder that the highest traditions of the ESU department are written in the very lives of those who have given everything in the line of duty," said Gerry Dowling, NYPD EMS commanding officer.

As the curtain fell during the ceremony, emotions rose, and 45 faces with 45 stories faced out from the wall. The NYPD honored all the ESU members who died in the line of duty, including 14 who were killed on 9/11, like John D'Allara.

"[It] means a lot to know that he will never be forgotten," Carol D'Allara, John D'Allara's widow, said. "[I'm] very touched that they would honor him in such a way."

John D'Allara also left behind two sons. One of them is now following in his father's footsteps, becoming an officer about a year and a half ago.

"Really carry on his legacy. This is his badge number as well," Carol D'Allara said.

Next to the wall and behind glass is a piece of that legacy -- John D'Allara's firearm. It was recovered from the World Trade Center months after the attack.

For John D'Allara's son, it's a physical connection to a father he lost, and a reminder of why he chose this life of service.

"I really wanted to help people. He helped people up until his last day. I would like to help as many people as I can while on this job," Nicholas D'Allara said.

And on the memorial wall, which was strategically placed at the ESU training school, the names and faces will continue to watch over the next generation of officers.

It's daily reminder of the courage, sacrifice and commitment to service that came before them.