(CBS News) NEW YORK - New York City is very close to putting back what terrorism took away.
Workers on One World Trade Center, the symbolic tower rising near Ground Zero, are erecting steel for the 100th floor on their way to 104.
It will be the tallest skyscraper in North America when its sculpted antenna reaches 1,776 feet.
The CBS Evening News asked several correspondents to go to the top with the iron workers walking the beams more than 1,000 feet in the air. Several declined. But Nancy Cordes and her crew, jumped at the chance.
Getting to the top of One World Trade Center is a job in itself. First you ride up to the 89th floor on two construction elevators. From there, a series of ladders are the only way up to the 93rd floor which has no walls and the sky for a ceiling because it was only built last week.
Tommy Hickey and Michael O'Reilly spend their days scaling foot-wide wide steel beams. They are part of an elite, four-man crew of ironworkers called "connectors."
"We connect the actual steel structure of the building, the steel skeleton and all the other ironworkers come in behind us," says O'Reilly.
Two enormous cranes lower the beams into place, then Hickey and O'Reilly bolt them together.
"What we are doing now, is setting that 100th floor," says Hickey.
How dangerous is it up there?
"Anything can happen, especially with us," says Hickey. "Fingers, toes, falls, very dangerous and the heights. We've just got to watch each other's back. That's why I say he is my brother -- I'm with him more than my wife, you know? You just got to watch every move you do, and he does so we don't hurt each other."
The day CBS visited, they were raising the "cocoon" -- a steel and net structure that surrounds the building for safety, so debris doesn't drop 1,200 feet to the street below.
Working seven days a week, they are now just six feet away from overtaking the Empire State building as the tallest skyscraper in New York, a status the twin towers held before they fell.
"It's a trophy to come here and do this, you know?" says Hickey. "Biggest job in the city."
Hickey is a fourth generation ironworker. His grandfather worked on the Empire State building. His father helped to build the South Tower. O'Reilly's father was terribly injured while building 7 World Trade Center in 1985.
"He was doing what I do now, which is connecting -- what me and Tommy do -- and he had fallen and was paralyzed," says O'Reilly. "So that ended my dreams of becoming an ironworker right then. And then 9/11 changed that all over again."
7 World Trade also fell on 9/11.
"Well, when the building came down it all happened for no reason, so (I felt) let me go in and rebuild it to honor him," says O'Reilly.
The higher they go, the more punishing the conditions become. It's 10-15 degrees colder here than at street level. High winds and fog often halt construction.
When the weather does cooperate, these ironworkers can move remarkably quickly -- erecting one floor every seven to ten days.
Down below 3,500 workers are welding beams -- laying metal rods - and pouring concrete. Building what the architects say will be the strongest skyscraper in the world.
"A lot of pride, yeah, in all these workers," says Hickey. "I mean, everybody is proud of what they're doing."