The path to the towers began with the idealism expressed at Seattle’s Century 21 Expo in 1962. Architect Yamasaki gained notoriety for his Federal Science Pavilion built for the World’s Fair, an event for which he had served on its advisory committee. The pavilion complex is now the Pacific Science Center, a city landmark. Yamasaki impressed visitors and the media as a modern architect capable of designing a magnificent structure, like a 21st century Alhambra, a place of beauty and serenity.

Yamasaki experienced racism in Seattle as a child of low-income parents raised in Japantown on Yesler Hill. He had helped his parents avoid Japanese incarceration on the West Coast in World War II by moving them east to live with him in his one-room New York apartment during the war. He had been subjected to brutal working conditions in Alaska’s canneries while studying architecture at the University of Washington. He came to believe in the power of architecture to uplift people in the face of the often dark realities of the modern world.

While the Space Needle has become the symbol of the fair, the “Space Age Gothic” arches of the Yamasaki Pavilion, as well as the outdoor pools and fountains, have become its architectural jewel. While some critics dismissed his work – Vincent Scully called an earlier Yamasaki project a “chirping aviary” – others loved it, including the Port Authority of New York and New Jersey representative, who saw it in person and was fascinated. After the show, Yamasaki was added to the list of architects being considered for their World Trade Center project in Lower Manhattan.

Detroit-based Yamasaki was selected to lead the design team. As the project evolved, what the Port Authority wanted turned out to be far from simple, but simply: build the world’s tallest buildings and beautify them.

Yamasaki had never undertaken such a large commission, but he had plenty of ideas. He developed an innovative structure with Seattle engineer John Skilling’s team that would give the Trade Center towers an unprecedented height (each more than 1,300 feet tall) with maximum rentable square footage – each floor offering approximately one acre of space. The buildings were supported not by interior pillars but by their exterior frames.

Skilling had worked with Yamasaki on the Science Pavilion’s remarkable space arches. While working on the design of the WTC, the two men also designed the IBM office building (now the 1200 Fifth building) located at Fifth Avenue and Seneca Street in downtown Seattle. At first glance, it looks like a miniature model of a Trade Center tower: narrow windows and an exterior structure that resembles stripes, with Gothic arches at the base. When the IBM Building opened in 1964, it added midcentury class to a downtown that had little of it.

The Trade Center project was more ambitious. Height and budget created limitations and problems, such as how to keep the 90-story towers stable against wind and sway, and how to protect them against fire? The demands for size and elegance seemed contradictory. During the design phase, Yamasaki was tempted to quit, but decided it was a “twice in a lifetime” commission, which he called “the greatest project ever “.

While Yamasaki had been criticized for being too decorative with his “aviary”, critics could not say the same about his clean design for the towers, a truly minimalist approach. The Twin Towers were not visually elaborate like some other classic New York skyscrapers. Their scale would be their message, and their dizzying height would signal global economic ascendancy. Yamasaki considered them a “beacon of democracy.”

Their unprecedented scale was undone by a terrorist attack in 2001. The best that can be said of their design and engineering is that many people in the buildings were able to escape because the towers did not not collapsed immediately after being deliberately rammed by fuel-heavy commercial aircraft. But that’s little comfort. Examining how the structures failed has been a painful part of the post-mortem of the attack.

Yamasaki died in 1986, but Skilling Tower engineer Leslie Robertson witnessed the 9/11 attack. He said The New Yorker shortly after: “There are all kinds of terrible things happening on this planet, which nature imposes on us. But this event… it was man against man but it was live on TV, and we watched it, and you could reach out and touch it… but you couldn’t do anything.

Even today, 9/11 is at the forefront of our politics. A candidate for the Republican presidential nomination has said he “wants the truth” about the September 11 attacks, suggesting it could be part of a US government conspiracy. Rudolph Giuliani, who gained worldwide fame as New York City mayor during the September 11 attacks, has been indicted on felony charges in Atlanta and faces disbarment in New York, raising questions about the the extent of his gap in relation to “America’s mayor”. Comedian Jon Stewart passionately advocated for health care for 9/11 first responders who suffered long-term illnesses from toxic exposures at Ground Zero. It’s an argument against America’s habit of forgetting.

September 11 is a time to remember the people and the tragedies of that day, the heroism and terrorism that were manifested in multiple acts in New York and beyond. The Twin Towers had become powerful symbols that attracted enemies and admirers alike, something no one really anticipated.