Rudy Giuliani was mayor of New York City on Sept. 11, 2001. Twenty years later, what he remembers most is the friend he lost and a stranger he saw in the sky. These are his words, as told to Susan Edelman.

It was election primary morning on Sept. 11, 2001. New York’s then-Mayor Rudy Giuliani was eating breakfast with friends at Midtown’s Peninsula Hotel when an officer on his security detail told him a plane had hit the North Tower.

“It sounds bad, we better get down there,” Giuliani decided. When he arrived at the World Trade Center, “it looked like Dante’s Inferno.”

“When we got to Saint Vincent’s hospital, I saw the stretchers and the doctors and nurses on the street, waiting for patients. It looked like a scene out of a war movie. On Canal Street, we heard a big explosion. Within a second or two, Bernie [Kerik, the police commissioner] called and said a second plane hit. On West Street, people were running and getting hurt by stuff coming down from the top.

“As I was looking up, I saw a man in the window on the 101st floor. It froze me for a minute — the image that comes into my head pretty close to every day. I felt like I knew what he was thinking: ‘Do I want to burn to death or jump?’ I saw the man jump.”

Then, he had a final encounter with his longtime friend and spiritual adviser, Father Mychal Judge, shortly before falling debris killed the beloved priest, who had just given last rites to a dying firefighter.

“Father Judge was walking toward the North Tower and crossed my path. We always had a joke — whenever I saw him I’d say, ‘Father, pray for me.’

“He always used humor to deal with stress. This time I could see fear on his face. He put his hand on my shoulder and said, ‘I’ll be praying for you.’

“When I heard they had found his body, that was harder than losing almost anybody, because he really helped me understand and empathize with people going through tragedy, going through death.”