SEPTEMBER 11 2001

Everybody remembers exactly what they were doing when they heard the news that the twin towers in New York were under attack. My colleagues and I were on the ground level at Place Ville-Marie. At the time, we did not understand what was happening. We heard a plane had crashed into the twin towers and it was news headline. There was nothing to worry about. I thought to myself, something happened to the building, The exterior will need major repairs or something like that.

After a while, everyone had to leave the premises, as a preventive measure. The authorities came and said they're shutting down because didn't know if it was an isolated attack in New York or something also happening in other major cities around the world. Later on, in the news it was made clear, this was a '' terrorist attack ''.

In Montreal, Place Ville Marie is a 47-storey cruciform office tower made of limestone, steel columns, aluminum and glass. It's the tallest building. The building rests on 4 anchor points for stability so it can resist strong winds. All the way at the top, a counter-clockwise rotating beacon on the rooftop lights up at night that can be seen as far as 50 kilometres away. The promoter Salvador William Zeckendorf hired Ieoh Ming Pei and Henry N. Cobb, a duo architects based in New York City.

Terrorists hi-jacked airplanes after passing airport security on September 11 2001.

Getting past the conspiracy theories

The year was going ok until September 11. We didn't know it then, but this horrible event was the start of some sort of loophole. It's like time stood still. Then eventually life life went on but with a ripple effect that was felt throughout the entire world.

After that the United States under President George Bush Jr. went to war to capture Saddam Hussein.

It was hard to begin to understand the magnitude of the destruction. Even today, we continue to think of the many ways to prevent this from happening. From a lack of security at the airport equipped with metal detectors, the building's poor management in this type of emergency situation and the role of technology to communicate effectively and lead people quickly toward the nearest exits.

We saw new measures put in place to ensure safety, strict protocols, travel rules and procedures at the border.

Even with all of this, there are many unanswered questions to this day about everything.

By taking a look back every now and them, we can move on while making sure history doesn't repeat itself.

The rules changed drastically to ensure people's safety while traveling.

One Tower

The project was moved to a new location away from were the World Trade Center used to be. It was not rebuilt on the ashes of ground zero.

On April 30, 2012 the new tower was completed while under president Barack Obama. It is a tall geometric shape made of steel and glass. It was designed by the architectural firm Skidmore, Owings and Merrill.

The cost was $3 billion or $1,150 per square feet and $ 3.9 billion near the end of the project.

The first tenant to move in was the mass media company Condé Nast after signing a lease before the end of the project, in 2011.

There are about four hundred surveillance cameras around the site, with live camera feeds monitored by the NYPD continuously and airport style security screening. Building security features like extra-wide stairwells, sprinkler systems and reinforced concrete walls.

But the CN Tower in Toronto exceeds One World Trade Center's pinnacle height by approximately 40 ft (12.2 m). Therefore it makes One World Trade Center the second-tallest freestanding structure in the United States and Canada.

Street view of One Tower in Manhattan.