<i>60 Minutes II</i>: Under Ground Zero

It started in Manhattan, nearly two months ago, at a place that will be known forever as Ground Zero.

Dan Rather reports on a once vibrant underground city-within-a-city that is now a 16-acre burial ground. It's a place where the effort to rebuild - both physically and psychologically - faces extraordinary challenges.

Almost two months after the attack on the World Trade Center's twin towers, there is still smoke in the air at Ground Zero. Subterranean fires still burn. It will be several more months before all the debris is carted away. Then there will be an even more daunting and dangerous and time-consuming clean-up job: digging up and repairing the tunnels and garages and underground mall beneath Ground Zero.

Ken Holden, commissioner of New York’s Department of Design and Construction, is the city’s point man in the effort. He says cascading debris from the tall towers destroyed not only this building – World Trade Center Building 6 – but a vast area underground.

"In Building 1 and when the building collapsed - large chunks of that heavy facade broke off. presumably from the upper floors, 90 or higher, and just crashed through the center of this building, crashing through the nine floors of this building and you’ll see when we go underground crashing through many of the concrete slabs that create the parking structure."

The debris, some of the individual pieces weighing 30 tons, hit the roof of building 6 like a cannonball, creating an open space that looks like an atrium. Offices were flattened like pancakes and driven several stories below ground.

"You can see right through," says Holden. "You can see desks, you can see lights hanging, fluorescent lights hanging down from the cable, this was wall-to-wall building, east, west, north, south, you can see the complete huge hole."

Because of the force and the weight of the falling debris, much of Building 6 is highly unstable.

There are cracks and fissures in the staircases and walls. It is still very dangerous. The deeper you descend, the darker and drearier and dustier it becomes.

A few days ago, Holden took a Rather on a tour. "You've got all those concrete blocks above your head so please just kind of keep an eye, try to stay out from underneath them," Holden told Rather as they walked. “They’re only being held on by wires.”

The air smelled of smoke. There was devastation everywhere. There was so much damage to the super-structure that it was surprising to see anything standing.

There are the huge columns, the huge exterior columns that support the exterior of the building, and you can see the force of the fire and the explosion has basically sheared these off.

Three floors beneath Ground Zero, they walked into what used to be a garage for the federal employees who worked in the building. Daylight streamed through, from a crater at the bottom of the atrium.

Said Holden: "Here, you get your firt sense of the collapsed parking structures, part of the atrium, the area I call an atrium, obviously it was not an atrium. You can see cars hanging off here, cars down here."

"The fire here was so hot, these cars are all burnt out. You’ll be able to see the aluminum hub cap has just melted right off. That is a puddle of aluminum from the fire."

Tens of thousands of people once came to these underground tunnels every day, not just to work in the towers and park their cars, but also to visit a vast, underground shopping mall. It was a city underneath the city.

It was "a very very vibrant place," Holden says. "Shops, restaurants, 15 to 20,000 people per building, between people that actually worked, you had the one and nine train going thought he middle of the complex, you’ve got the PATH trains, I mean this is a huge - this was a mini-city."

The descent was pitch black, disorienting, and slippery. The floor was slick with oil and gas from abandoned cars. They had been warned the floor could collapse at any minute.

"“In a normal world, I would not want to take anybody to walk here," Holden said, pointing out deep cracks in the concrete.

The PATH commuter rail line is six stories below Ground Zero. Miraculously, no one died in the station on Sept. 11.

"Standard procedure when there is a fire is to evacuate, so all three PATH trains and the subways were evacuated when the buildings were on fire so when they did collapse nobody was injured,” says Holden. “We lost a lot of people but we saved a lot more than we lost."

Some 35,000 commuters used to arrive in the station from New Jersey every day. But everything stopped just five minutes after Tower 1 tumbled down six stories overhead. There is an empty PATH train there. Fortunately, there was nobody on the train. "It is pretty eerie," says Holden.

It may take two years before the trains start rolling into the station again, and even longer before a nearby subway line will be fixed. There are hundreds of miles of wires, pipes and cables to be replaced. By the end of next year, Holden hopes to have his area above and below Ground Zero cleared up. It will cost $2.5 billion. It may cost twice that much, when lawsuits and legal claims are added in.

They will likely have to remove over a million tons of debris. "We have probably removed somewhere in the area of 400,000 tons," says Holden. "The initial estimates we worked out with FEMA, the Federal Emergency Management Agency, and the Port Authority, were somewhere in the vicinity of 1.2 million tons, so we are probably about a third of the way through."

It will be a daunting task. "We'll get it done; we'll get it done," says Holden. "This is New York City. This is the greatest city in the country, the greatest city in the world. We took one on the chin, knocked us on our butt but, like all New Yorkers, we'll pick ourselves up, dust our clothes off and we’ll get back to doing what we do best.

But removing the debris that is underground is a logistical and engineering dilemma. When the Trade Center complex was built 30 years ago, an enormous retaining wall, called a slurry wall, was constructed below ground. It was designed to prevent water from the Hudson River, which is just two blocks away, from flooding the six-story basements. The wall, nicknamed the "Bathtub," is three feet wide and 60 to 70 feet deep.

Holden showed Rather the wall during their tour. "The water table here is extremely high because we are so close to the river, that special construction techniques were needed."

The wall was supported by the floors in the basement levels. These floors have now buckled. Holden’s engineers will have to shore up the wall to prevent it from collapsing.

"We are drilling through the three-foot wall, drilling 85 feet or so down to bedrock," Holden said. "We drill 35 feet into bedrock then we take basically the same kind of cables they use on bridges, grout it up, concrete it up, wait three days for it to cure, and then they tension those cables and that sustains the wall."

Holden was concerned about the structural integrity of the wall when he started demolition nearby. His engineers may have to install more than 1,000 cables to hold the wall up from behind. It is nerve-wracking work. Saving the wall is critical. If the tunnels flood, the water could pour into the nearby train and subway lines. It's a frightening prospect.

Holden is under pressure to get the job done. But he knows he can’t lose his sensitivity or perspective.

"About two weeks ago... a father firefighter was walking around asking us to hold off on the road building operation. (He) pointed to a road to his left and says 'You guys have already buried my best friend over here, and I'm looking for my son over here,' and he was pointing to the area where we were building another road. I held off on the road building for the rest of that afternoon, talked to the chief, and the chief understood that we needed to continue with the debris removal. And as I was talking to the chief, I saw out of the corner of my eye the father going through, going up to the debris pile with a spade and picking up spadefuls of debris, looking for his son in that manner and then there were spadefuls back and then continued to climb and look for spadefuls. (That) probably ranks as one of my more poignant moments."

Firefighters and other rescue workers still search round the clock at Ground Zero, looking for the bodies of the thousands of people who died here.

Holden is aware of the uniqueness of this site: "In order for me to work here everyday, I think I have to segue away from the sacred ground considerations, and move towards a construction site (mentality) but I think you can't work here without being cognizant that there are people here suffering here, there are dead bodies here, and there is a need to treat this ground in a manner different than you woud any other construction site."

Since the attack at Ground Zero, Holden and his troops have been down in the rubble almost every day. It hasn't been easy. But America is at war, and Holden plans to win.

"I think my attitude is probably the same attitude that most of the guys have down here, working on a day-to-day basis, working on the Pile, which is summed up by a quote from Winston Churchill 60 years ago when the Nazis were bombing Great Britain and the British people were pulling out their family, their friends and their neighbors from the rubble. Winston Churchill said 'We shall not fail, we shall not falter. We shall not weary, we shall not tire. Just give us the tools and we’ll finish the job.'"

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