A cavernous museum on hallowed ground is finally nearing completion, far below the earth where Manhattan's twin towers once stood.
Amid the construction machinery and the dust, powerful artefacts of death and destruction have assumed their final resting places inside the National September 11 Memorial & Museum.
A vast space that travels down to the bedrock upon which the towers were built, the museum winds its way deeper and deeper underground, taking visitors on a journey to the very bottom.
Already on display are several pieces of mangled steel and metal recovered from the World Trade Centre towers, each one telling a different story of the terrorist attacks that killed nearly 3,000 people.
The first relics that visitors will see are two massive pieces of structural steel that rose from the base of the North Tower. Now the rusty red columns soar above ground into the sunlit glass atrium that encloses the entrance to the museum. "They're so large - about 70 feet [21 metres] tall - that we built the museum around them," explained Joseph Daniels, president of the memorial and museum.
Down a long ramp, visitors will peer down to glimpse the last piece of steel removed from ground zero in 2002, which sits inside a gaping silvery chamber that drops to the lowest level of the museum.
Further down the ramp, visitors will discover a mangled and twisted piece of steel that Daniels calls "impact steel". That's because this piece of the building was actually destroyed by the impact of Flight 11 slamming into the North Tower.
"You can see how, at the bottom, the columns are bent back," Daniels said. "That's because Flight 11's nose, when it pierced the building, it bent steel like that."
When completed in the spring, the museum will transport people through time from events leading to the 9/11 attacks all the way to the events of today. And even when its doors open, the museum will always remain a work in progress.