September 11, 2001, changed the United States forever. Nearly 3,000 people were killed, including men, women and children. Americans at home watched in terror as two planes, hijacked by terrorists, crashed into the World Trade Center towers, forcing those inside to fall or leap to their deaths.

Completed in 1973 as the tallest buildings in New York City, the North Tower rose to 1,730 feet with a large antenna and the South Tower stood at 1,362 feet high. Each massive tower weighed more than 250,000 tons and contained 110 stories.

Inside there were 99 elevators, 21,800 windows and each floor was an acre in size. The North Tower and South Tower provided nearly 10 million square feet of office space for about 35,000 people and 430 companies.

The World Trade Center complex even had its own zip code, 10048, and the Twin Towers were surrounded by five other buildings including a police desk in 5 WTC. The towers attracted roughly 70,000 tourists and commuters every day.

Before September 11, the Twin Towers were a symbol of the city. However, when the towers fell, the city fell with them. However, life in the Big Apple could not stop and just hours after the attack, then-Mayor Rudy Giuliani promised to rebuild.

Four months later, newly-appointed Mayor Michael Bloomberg pledged that he would “devote himself to building a better New York.”Giuliani encouraged buildings to build low, according to Quartz, and U.S. Model Building and Fire Codes were revised pending an investigation.