Still standing 25 years on from the attack that changed the world

Paul Gyulavary still has a flag bearing the names of those killed in 9/11 hanging in his home.

Their worlds were punctuated by hate. They refused to bend to its power.

On a cold September night 25 years ago, Paul and Yvonne Gyulavary were getting ready for bed.

The dinner dishes had been washed and stacked, the lights switched off, their three young children tucked in with a bedtime story in their mountain home outside greater Melbourne.

Paul went to bed and flicked on the TV, as Yvonne stepped outside to fetch some logs to top up the fireplace.

Then something hit her.

"I just had this feeling," she said. "The air felt so terrible to me. I had to get inside."

She paused.

"I was scared of the air."

The Gyulavarys keep their fire going deep into spring in Victoria.

She hurried back, locked the door, and joined her husband.

On the television, a punctured tower billowed smoke against a crystal-blue sky.

Yvonne presumed Paul was watching an "Armageddon movie".

Then, United Airlines flight 175 thundered into the south tower of the World Trade Center.

This was no horror movie.

"The first plane, you think it's an accident," Yvonne said.

"The second plane cannot be an accident."

Halfway across the world, downtown New York was drowning in ash and debris from the wreckage of the falling Twin Towers.

2,977 people died in the September 11 terrorist attacks, including 10 Australians.

Their deaths were broadcast live on TV.

The replays were inescapable.

A loved one's murder, on loop, for all to see.

Among the dead was Paul's twin brother, Peter.

Peter Gyulavary moved to New York in the mid-1980s to further his architectural career.

He fell in love, started a family and moved upstate, where he spent weekends meticulously restoring a three-storey Victorian-style home.

Everything from the roof shingles to the walls was obsessively researched, then refurbished using the original methods — save for the paint job.

"Bright yellow with dark green trim," said Paul, "an homage to home".

"He walked me through the house and he put my hand against the plaster and said, 'Feel this.'"

"It was like running your hand over butter."

In the weeks leading up to September 11, Peter had been working on a light rail project in St Louis.

When the first plane hit, Paul presumed his brother was still out of town.

He had to be.

"I'm ringing and ringing and ringing and ringing [New York], and there's no answer," Paul said.

Three days later, the Gyulavarys learnt Peter had been in his office in the South World Trade Center and was still missing.

Hours of waiting turned into days and weeks.

Hospitals were searched.

Soon it became clear that Peter Gyulavary was dead.

Ten weeks later, on the eve of Thanksgiving, Peter's body was found.

Paul remembers seeing the American flag draped over the coffin as it was delivered to the home his brother had poured his heart into.

"It never occurred to me that his body would be found," Paul said.

"I just thought his body would be in fragments of dust and ground zero."

"It was like he died again."

The Australian twins in the Twin Towers

Andrew Knox also worked in architecture in New York City, in the North World Trade Center, opposite Peter Gyulavary.

Like Peter, Andrew was a twin.

His brother, Stuart Knox, was a school teacher back in Australia, just like Paul Gyulavary.

Two towers.

Two sets of twins.

After the first plane hit, Andrew ran from his office on the 103rd floor to the roof of the North Tower with his colleagues.

They huddled together on a ledge.

Before long, they were engulfed in acrid, black smoke.

Eight days later, back home in Australia, Stuart was asked to recount his brother's final moments to a hungry media pack.

Sitting in front of a swathe of microphones and cameras, Stuart, looking more like a nervous sporting debutant than a grieving brother, read from an email written by his brother's boss in New York.

"We had Andrew on speakerphone at first, and then we heard the screams and him yelling, 'We're all going to die,' as they ran up the last flights of stairs to the roof," Stuart read from the email.

"Then I heard Andrew's co-worker say, 'Andrew, I can't breathe anymore.' And Andrew replied, 'I can't breathe either.'"

Before he left for New York, Andrew was a Labor Party member with political aspirations.

Stuart fronted the press on the party's advice.

They'd said the media would stop hounding him if he did.

"It didn't quite work out like that," Stuart said.

"It snowballed."

Stuart has never had any interest in retaliatory fights on his behalf.

He's marched against the War on Terror.

"We know from history that war claims innocent lives … for our families, that occurred in the name of justice, and that was some of the hardest stuff to see," he said.

Andrew Knox and Peter Gyulavary never met.

But their brothers have connected in the years since their deaths.

"We met each other in New York once and that was powerful," Paul said.

"We went to Ground Zero together.

He found his brother's name, I found mine."

The surviving twin brothers have made limited media appearances together since the attack.

"It's the old thing: You don't have to explain."

They share an unspoken understanding.

"There was a bond.

That was an awful bond to have formed over something like that," Stuart said.

"Like survivors of a shipwreck, on an island, in it together."

Andrew's death has had a profound impact on Stuart's daily life.

Some days are better than others.

"Twins are one soul that separates to form two people," Stuart said.

"One of the things I carried around for a while was the question of, 'Was it supposed to be the case that [only] one of us was taken?

That God had said, 'It's Andrew's time?'

I guess that came from a real difficulty in finding acceptance around why this happened."

Remembering the Australian lives lost

Alberto "Pocho" Dominguez was a passenger on the plane that struck the North World Trade Centre.

Kevin Dennis, who held dual British Australian citizenship, was working on the 101st floor of the North World Trade Centre when he was killed.

Elisa Ferraina was 27 years old when she was killed while working at a conference on the 106th floor of the North World Trade Centre.

Craig Gibson worked as an insurance broker on the 94th floor of the North World Trade Centre.