The East Village loft was abuzz with activity.

The assistants to the Pulitzer Prize-winning photographer I came to interview were hard at work in the front office. The loft was quite spacious and tastefully decorated with big, colorful prints covering the walls and photography equipment was scattered throughout the place. In the main room sat a lone figure dressed entirely in black (including his hat) with his feet up on a table. He was nursing a bottle of Corona beer and just staring off into space, deep in his own thoughts.

"I'd love to know what he's thinking about," I thought to myself as I crossed the cavernous room. When he saw me walking towards him he quickly jumped up and extended his hand. "I'm Eddie Adams," he said with a firm grip and a friendly smile.

Catch the 'War Stories Classic: The Tet Offensive,' Monday, February 2 at 3 a.m. ET

Eddie Adams was a giant in the world of photography. In a career that spanned 45 years, he had done extensive work for the Associated Press, Time and Parade magazines. He also had a lot of high-profile clients in the world of fashion, entertainment and advertising. But I hadn't come there to talk about the glamorous world he now inhabited. I was working on an episode of "War Stories with Oliver North," about the Tet Offensive during the Vietnam War and I was there to talk about one picture he took as a war correspondent. A single photograph that changed two lives: Adams's and one of the men in it.

On February 1, 1968, Adams was in Saigon on assignment for the Associated Press. The Tet Offensive, when the Vietcong began attacking within Saigon, was in full swing. He and an NBC camera crew were walking through the Chinese section of town when they saw South Vietnamese police pull a man out of a doorway and lead him down the street.

"Most photographers or most news people," remembered Adams, "when they grab a prisoner and they're going to lead him to a wagon, it's natural, you just photograph him until he's out of sight."

But there was no paddy wagon.

"They stopped on a corner," Adams said. "And out of nowhere to my left I see this guy walk in and I'm 5 feet away. And as soon as he got close to him, I see him move his pistol. And I thought he was going to threaten him like the police do sometimes. They always threaten somebody. And he went for his pistol and as he raised the pistol up, I raised my camera and took a picture."

That picture sent shockwaves around the world.

"Within 24 hours, all the messages start coming in from New York," Adams recalled. "Who's this guy? The picture is being displayed page one everywhere."

The public was outraged by the seemingly cold-blooded killing. The anti-war movement began using the photograph in demonstrations. The man pulling the trigger was Saigon Police Chief General Nguyen Ngoc Loan and the man he shot was a Vietcong sniper named Nguyen Van Lem.

"I tell people that two lives were destroyed in that photograph," said Adams. "The person who was shot and the man who pulled the trigger. America condemned him. They said that he shot somebody in cold blood. And I tried to tell people, there are good guys and bad guys in every war. At that time, he was a good guy. He was fighting for America with America. Aren't you supposed to shoot the enemy? I mean, that's what he did. And so he's condemned?"

The photograph was awarded the Pulitzer Prize for breaking news photography. But in his typical self-effacing manner, Adams admitted to me that he really doesn't understand the acclaim the photograph has received. "I honest to God don't get it, even today," said Adams. "I really mean this. It's not the flag raised on Iwo Jima."

Eddie Adams died at age 71 of amyotrophic lateral sclerosis, known as Lou Gehrig's disease, on September 19, 2004.

Steven Tierney co-produced "War Stories: The Tet Offensive"