More than 12 years after the worst terror attack ever on American soil, there's one image in particular from 9/11 that Rudy Giuliani can't get out of his head.
"I think the most difficult moment I had as mayor of New York City was when I arrived at the World Trade Center," Giuliani recently told "Oprah: Where Are They Now." "Not really knowing how bad it was, not really emotionally grasping all of that until I saw a man throw himself out of the 100th floor. And that's an image – that's an image that stayed with me forever, almost every day it comes up in my mind somehow. And then after that I just decided well, its part of me and I have to live with it."
Like many Americans, Giuliani experienced painful, personal loss on September 11. "I was very, very close to Father Michael Judge, who was the chaplain of the fire department, and he was the first person discovered dead after the attack," Giuliani says.
When he was having a bad day as mayor or dealing with a personal problem, Giuliani says Judge would leave encouraging notes for him. "And he would say, 'I know you're really feeling down, but I want you to remember that God knows that you were with me three nights ago and you stayed for six hours at firefighter so-and-so's bedside. Nobody else has to know that, but God knows it. And we all do things that are wrong in life, but we make up for it by doing things that are good.' And it used to make me cry," Giuliani says.
"Probably the most difficult loss to deal with on September 11, immediately at least, was his loss," he says about Judge.
Also in the video, Giuliani talks about his reaction when Osama bin Laden was killed by U.S. Navy SEALs. It was long after Giuliani had left office, and like most of the world, he found out when President Obama made his television address.
"Oh, I remember it exactly," he says. "I was in my kitchen in Manhattan and I was watching 'Geraldo Rivera.' And I just looked up and I saw a banner go across the television screen that said that the President of the United States was going to address the country.
"I felt this great feeling of –- it was like a feeling of relief -- because I knew how this would satisfy the sense of justice that so many of the thousands and thousands of people that I've met that lost firefighters, police officers, husbands, fathers, children," Giuliani says. "And I knew over the years how much this idea that Bin Laden was still out there, still possibly could do something like this again, I knew how this hung over them."
In the below video, "Oprah: Where Are They Now?" executive producers Jill Van Lokeren and Julie Simpson join HuffPost Live to talk more about the episode featuring Giuliani.