09/09/2011 04:30 EDT | Updated 11/08/2011 05:12 EST

Calgary man would sooner forget what he watched unfold on Sept. 11

PORCUPINE HILLS, Alta. - Try as he might, Dan Denette will never forget the shoes.

Of all the indelible, unforgettable images from the day the Calgary ironworker became a chance witness to history — the stricken, doomed towers, the landing gear in a debris-strewn alleyway, the hand-lettered poster depicting a missing husband and father — that one in particular stands out.

"Everywhere you looked, there was people's shoes," Denette, 53, told The Canadian Press in an interview.

"I thought, 'These shoes belong to individuals who were in this tower.' It's funny how something that simple sticks with you. You take a brawl in hockey and you remember the gloves and the sticks and the helmets on the ice.

"There, it was shoes."

It's just one of the many difficult memories Denette has of Sept. 11, 2001, the day he was supervising a construction project in a building on East 41st St. in Manhattan, several kilometres from the World Trade Center.

When he heard someone shouting that an airplane had crashed into one of the twin towers, he and his colleagues rushed to the 25th floor, where the spectacle of the north building in flames quickly gave way to the horror of seeing a second plane suddenly barrelling into the south tower.

"We were close enough that we were able to see the building was burning, some people who were leaping from the building, and that kind of stuff," Denette, 53, said in an interview with The Canadian Press.

Denette's weekend getaway in Porcupine Hills, about 200 kilometres southwest of Calgary, is a tranquil place where the only sound is the buzzing of the insects and the wind rustling in the trees — a pastoral setting far removed from the bustle of lower Manhattan.

"Some people become part of history because they're there, but I don't consider myself to have a big story to tell (just) because I was in New York on 9-11," he said.

"I would sooner not have been there and not be here telling the story."

Denette has resisted talking publicly about his experience. No one but his son, Canadian Press photographer Nathan Denette, had ever seen the pictures he took that day, a grim chronology of the final hours of the World Trade Center.

One shows the now-familiar silhouette of the stricken north tower, a column of thick black smoke spiralling into a clear blue sky, after it was hit by American Airlines Flight 11 at 8:46 a.m. ET. United Airlines Flight 175 struck the south tower some 17 minutes later; Denette's second photo shows both towers in flames.

Denette's final two photos tell the rest of the story: in one, the first tower has vanished. In the other, both buildings are gone, replaced by a dense column of relentless smoke, dust and debris.

"New York is a really busy city; It's constant noise," Denette said softly, his wife Tracy making lunch in the kitchen nearby.

"When it came down it was almost like it sucked the noise out of the city. It was almost as if there was silence — and you don't hear that in New York."

In the aftermath, Denette and his co-workers watched solemnly as a tide of people, the lifeblood of lower Manhattan, came staggering up the street, refugees of the worst terrorist attack in American history.

"It looked like coal miners coming up the street," he recalled. "We all just sort of stood there. I don't think anybody really said anything."

Even a decade later, the memories are still painful.

"Tracy and I pulled these pictures out the other day and I had a bit of a cry over it," he said. "I think being in New York at that particular time is probably one of the most unfortunate events of my life."

It was Denette's son Nathan who convinced him to tell his story on the eve of the 10th anniversary of the attacks.

"My dad is an old-school, born-and-raised Albertan who works the big steel as an ironworker ... feelings and thoughts are something that old-school men don’t talk about," Nathan Denette said.

"You know better than to ask when it comes to horrific events, such as what he saw on 9-11."

Denette and his colleagues were summoned to Ground Zero in hopes that their expertise would be useful as the frantic rescue efforts began to ramp up. But it soon became apparent that the devastation was too great.

That's where he saw the airplane wreckage, the posters pleading for help, the bedraggled faces of dejected rescue workers — and the shoes.

"It was a real useless feeling while we were down there," he said.

"The police and the fire department just looked like a beat-up group of individuals. They had just been whipped. You could just see it in their faces — where would you even begin?"

Denette described Sept. 11 as the biggest tragedy to occur in his lifetime, one comparable with the Japanese bombing of Pearl Harbour 70 years earlier. It led to a brief phase where he was afraid to fly, he said — fearful every time a passenger got up from his or her seat.

It's a fear he's chosen to confront now in honour of the legacy of those who died, citing the legacy of the Holocaust to illustrate the importance of ensuring the memory of such an epic tragedy doesn't fade with time.

"Let's record what has happened here, because somewhere down the road there's going to be some son of a bitch who says this never happened," he said.

"This did happen, and I think it's important to remember — not because of revenge or anything like that, but because it is a part of history."

It's also, he's hoping, somewhat therapeutic.

"For the longest time, I really had a lot of trouble even talking about it without getting pretty emotional, Denette said.

"I think years heal, right?"