Building a legacy


The National September 11 Memorial & Museum’s team members had an emboldening sense of mission. They would need it.




The project team had a clear objective: to answer destruction with creation. A US$700 million initiative would build a memorial and a museum on the same site in New York, New York, USA where two skyscrapers collapsed after hijacked jetliners flew into them on 11 September 2001.

Over the next 13 years, the team would have to keep its sights fixed on that goal as it encountered logistical predicaments and environmental disasters that at times became so extreme it seemed the team could not possibly recover.


Immediately after the World Trade Center’s twin towers fell, Lend Lease—one of the world’s largest construction management companies, headquartered in Sydney, Australia—became involved in the recovery effort, overseeing the entire cleanup operation. For 265 days, the Lend Lease team coordinated and worked with hundreds of New York City police and fire department personnel and thousands of volunteers to complete the recovery phase, clearing more than 1.6 million tons of debris from the site.

“I came down on that first day to help with the rescue,” says Neil Clarke, senior project manager and vice president, Lend Lease, New York, New York, USA.

As the project moved from the recovery phase to rebuilding the site as a memorial and museum, the National September 11 Memorial & Museum foundation hired Lend Lease as the lead contractor. The Port Authority of New York and New Jersey was assigned responsibility for building the memorial, while the foundation focused on the integrity of the design.

“At the time, it was forecast to be a three- to five-year project,” says Brian Santos, a Lend Lease project manager. “But over the life of the project, the schedule grew until the memorial deadline was finally pushed to the tenth anniversary.”

In 2006, after five years of planning and design competitions, the project team had a design in place for the memorial and museum and began to work on the site’s foundation.

That year, the team hit its first delay. The project was put on hold to conduct value re-engineering, which meant reassessing the initiative’s goals and projected costs to rein in spending and to accommodate the concerns of stakeholders such as the family members of the September 11 victims. Resulting changes included fewer museum galleries and visitor entrances.



“At the time, it was forecast to be a three-to five-year project. But over the life of the project, the schedule grew until the memorial deadline was finally pushed to the tenth anniversary.”

—Brian Santos, right, with Neil Clarke, Lend Lease, New York, New York, USA

The exposed section of the original slurry wall visible to the public

The exposed section of the original slurry wall visible to the public

When the project was restarted later that year, the Lend Lease team set out to complete one of the most challenging aspects of the design: maintaining the integrity of the site’s original slurry wall, which had kept the nearby Hudson River from flooding the site after the Twin Towers fell.

“No one had ever built something like that [wall] before at that scale. It was one of our biggest challenges.”

—Brian Santos

The designers wanted to preserve the wall within the museum as a testament to the survival and determination of the American people, but the wall needed to be reinforced for structural reasons, Mr. Santos explains. So the Lend Lease team had to construct a retaining wall, which would be 70 feet (21 meters) tall and 80 feet (24 meters) wide, behind the exposed slurry wall.

“No one had ever built something like that before at that scale,” Mr. Santos says. “It was one of our biggest challenges.”

To construct the new wall, the team had to excavate from street level, sometimes digging by hand to avoid damaging the existing slurry wall. The retaining wall now serves as the primary barrier holding back the Hudson River, and it relieves pressure placed upon the 36-foot (11-meter) exposed section of the slurry wall visible to the public within the museum.


From the start, the site was dominated by multiple project teams working on different aspects of the reconstruction effort. While Lend Lease oversaw the memorial and museum, other teams worked on the train station, the hub access where visitors would enter the train station and connecting structures, and the technical infrastructure to support the space.

The project leaders and their teams had to work together, negotiating access to space and roads, and making sure efforts in one area didn’t conflict with work elsewhere.

“Trying to organize so many different elements of the project was a constant challenge,” Mr. Clarke says. “It was probably the toughest environment, from a coordination standpoint, that I’ve ever worked in.”

As a result, Mr. Santos, who oversaw scheduling, always had to have several alternate plans in place, knowing they would be constantly revisited and revised based on the latest set of requirements and stakeholder needs.

Workers deal with the aftermath of Hurricane Sandy in 2012

Workers deal with the aftermath of Hurricane Sandy in 2012.



“Most projects have a plan A and a plan B. This one ran through the whole alphabet,” he says.

Construction progress as of July 2012

Construction progress as of July 2012

The Lend Lease team leaders tried to keep communication as open as possible, through regular site meetings and feedback reports to stakeholders. However, Mr. Clarke says, “you can influence, but you can’t always control.”

Meanwhile, the project approached the tenth anniversary of the September 11 attacks—the memorial’s scheduled completion date.

“Eventually, every delay that came up had to be mitigated because we couldn’t miss that deadline,” Mr. Santos says. That meant bringing in extra workers and working overtime to make up for lost time. Then the team faced a new dilemma.


While the project team endeavored to influence active stakeholders, there was one element over which it had no control at all: the weather.

During the winter of 2010-11, the third snowiest in New York history, the project site, which was entirely outdoors, got hammered by snow. Lend Lease used up its snow removal budget in the first two weeks of the season, and the team struggled each day just to clear space to work, Mr. Clarke says.

“We just had to do what we needed to do to make it work,” he says. That involved working constant overtime and rotating teams to use the limited space available.

Despite the tough conditions, Lend Lease never had trouble keeping its workers engaged. “We didn’t need to motivate them,” Mr. Clarke says. “Everyone wanted to be a part of this project.”

That commitment propelled the team toward its deadline. On the tenth anniversary of the September 11 attacks, the memorial opened in the exact spot where the two skyscrapers once stood, with twin reflecting pools in the towers’ footprints and the largest man-made waterfalls ever built in North America. The pools are fenced by a bronze parapet etched with the names of the 2,983 victims who died on that day.

“Going to that opening ceremony with all the families made it worth it,” Mr. Santos says.

The Lend Lease team members were far from done, however. They still had to finish the museum, which was being built below the memorial.

“We didn’t need to motivate [workers]. Everyone wanted to be a part of this project.”

—Neil Clarke, right




By early October 2012, the team had completed all of the drywall for the museum and installed most of its electrical systems, elevators, escalators and main artifacts.

Then, with the project end in sight, bad weather struck again. In late October, Hurricane Sandy, the deadliest storm of the 2012 Atlantic hurricane season, flooded much of the city—including the museum. The storm filled the nearly finished space with 8 feet (2 meters) of water.

“It wiped out most of what we had in place,” Mr. Santos says.

For days, while the site remained filled with water, the site’s project owners figured out what to do. Logistics played a determining role, Mr. Clarke says. “All of the World Trade Center projects got flooded out, and we couldn’t pump water out of one site unless all the project teams worked together and we pumped it out of all of them.”

The project leaders held daily meetings to determine how to draw the water out of the entire site and into the sewer system slowly enough that it wouldn’t overwhelm the infrastructure.

After 10 days, team members finally got back inside the museum—and started tearing everything out.

“We had to throw it all away and come up with a new plan,” Mr. Santos says.

Fortunately, the museum artifacts were rescued and cleaned, but everything else—including all of the electrical components, floors, walls, elevators, escalators and most of the construction equipment that had been on-site—had to be replaced.

As a result of the disastrous flooding, the museum’s opening date was pushed back from September 2013 to May 2014. The completed museum features artifacts from the towers and an exhibition that explores the day of the attacks.

“It feels bittersweet now that it is done,” Mr. Santos says. “There were times when it seemed like this project would never end, but it has.”

“It’s an amazing facility,” Mr. Clarke adds. “Millions of people from around the world will come to this site and see what we’ve accomplished. Our company will forever look at this project with great pride. It was probably the toughest project I’ve ever worked on, but it was an honor to be a part of it.” PM

The plaza in front of the main entrance to the museum

The plaza in front of the main entrance to the museum




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