In the skies over Lower Manhattan, a symphony of steel plays five days a week, and what you hear when you reach the top of 1 World Trade Center is the sound of ambition.
The iron workers building America's tallest tower, 1 World Trade Center, are putting their fingerprints all over the skyline of Manhattan.
Iron worker Thomas Hickey's father worked on the original twin towers, and his grandfather helped build the Empire State Building.
"This business is built on speed,” says Hickey. “Get it done, and get it done fast and safe."
1 World Trade Center is going up at a rate of about one floor a week. The project began in 2006 and is expected to be finished in early 2014. It will stand 1,776 feet tall.
One of the youngest iron workers on the project is 24-year-old Kevin Sabbagh.
"Every day something hurts when you go home -- every day," says Sabbagh. “It's fun. My friends think I'm crazy and I guess this proves them right."
To handle steel beams that weigh more than seven tons, iron workers first have to pass tests, then apprenticeships.
"What we do is very competitive. The best of the best are up here," says Mike O’Reilly, an iron worker just like his father.
Putting together the puzzle pieces takes dexterity balance and whole of lot of guts.
"It doesn't matter to me if I'm a foot off the ground or 10,000 feet," says Peter, a member of the Mohawk nation, a Native-American tribe with a history of top-notch work on high steel. He did not want his last name used.
Peter, like all of the iron workers NBC New York spoke to, says 1 World Trade Center is more than just another job. It's a landmark and a tribute to the victims of 9/11.
"I look at it like we're building this for them, not just the city and the United States, this is going to be something for them for the people who lost their lives," says Peter.