NEW YORK (AP) ― Gray dust blankets everything in the subterranean halls of the unfinished National September 11 Memorial & Museum. But while the powder may look ominously like the ash that covered lower Manhattan after the terrorist attacks, this time it is a product of rebirth, not destruction.

After a yearlong construction shutdown because of a funding dispute, and additional months of cleanup following a shocking flood caused by Superstorm Sandy, work has been racing ahead again at the museum, which sits in a cavernous space below the World Trade Center memorial plaza that opened in 2011.

About 130 workers are at the site each day and there is much left to be done, but officials with the museum said the project is on track to open to the public in the spring of 2014.

Some of the museum’s most emotion-inspiring artifacts already are anchored in place.

Tears rolled down Anthoula Katsimatides’ cheeks Thursday as she toured halls holding a mangled fire truck, strangely beautiful tangles of rebar and the pieces of intersecting steel known as the Ground Zero Cross.

“It makes me sad,” said Katsimatides, whose brother John died at the trade center. But it’s also inspiring, said Katsimatides, who sits on the museum’s board. “Seeing it come to fruition is pretty intense.”

Work on the museum was halted for nearly a year, starting in the fall of 2011, because of a money fight between the memorial foundation and the Port Authority of New York and New Jersey, which owns the trade center site.

In retrospect, that slowdown was a blessing. Shortly after the two sides worked out their differences, Superstorm Sandy sent the Hudson River thundering through lower Manhattan and filled the museum cavern with 7 feet (2. 3 meters) of water.

The flood destroyed interior walls and electrical circuits, but the construction delay meant that hundreds of artifacts and exhibits that might have been in the museum still hadn’t been fabricated or were sitting safely in storage. There was minor flash rusting to one of the fire trucks that had already been lowered into the space, but the damage was repaired by conservators and isn’t noticeable today, said National September 11 Memorial & Museum President Joseph Daniels.

Today there is no sign that there was ever a flood. Daniels said there has been “almost indescribable” progress on construction since the storm.

Structural work appears mostly complete on the glass pavilion and wide staircase and ramp visitors will use to descend into the museum, past two towering “tridents” that once helped form the distinctive base of the twin towers. Once silvery, the columns were stripped bare by the fires on 9/11 and are now the color of rusted, raw steel.

From a mezzanine, patrons will be able to peer into a deep, nave-like hallway nicknamed the South Canyon. The hall’s high western wall will eventually be covered with artwork that people around the world made in tribute to the victims after the attacks. Another exhibit will feature supportive notes and letters.