(CBS News) NEW YORK - Seven stories below street level, Joe Daniels showed us the 9/11 museum, still under construction. Daniels, president of the September 11th Memorial and Museum foundation, thinks the 10 million people who have visited the World Trade Center memorial since it opened two years ago will come back.
"I think those are our most likely visitors," Daniels said.
While the museum won't be finished by this year's 12th anniversary of the 2001 terrorists attacks, Daniels promises it will be built in eight months.
"There is no doubt that it will be done by next spring in advance of the next anniversary," he said.
Financial disputes with the Port Authority of New York and New Jersey, the transportation agency that owns the 16-acre World Trade Center site and oversees its rebuilding, brought construction to afor last year.
The construction is also complicated. The underground museum is being built under the eight acre memorial plaza, whereout this May with three other towers on the way up. A new transit hub is being built about a block from the museum entrance.
Finally, though, museum renderings we've seen for years are becoming a reality. At the museum's entrance, there are giant steel tridents that once held up the twin towers' walls. There is the preserved "survivors staircase," which hundreds Trade Center workers used to escape the attack. Down below stands the last steel column, decorated by recovery worker graffiti, that was removed from the site after a nine-month cleanup. A visit to the museum will reveal archaeological artifacts such as an excavated base for south tower columns now visible at bedrock.
"I'd put us in the 75 percent-there stage, although this last 25 percent is some of the most difficult work, which is the installation of the exhibitory itself," Daniels said.
Demolished fire trucks and ambulances and other chunks of salvaged steel are already in place.
"These stand in a sense as our silent witnesses to what happened; they give testament to the scale of the destruction," said lead exhibit designer Tom Hennes.
His Manhattan firm Thinc has created a number of interactive exhibits. For example, toward the end of the museum, in front of a large piece of steel bent by the towers' collapse, visitors will be able to write their feelings about the reminders of a most tragic day on screens. Their writings will be projected in real time onto a large screen mounted on the museum wall.
"I think people will be angry; they'll be sad; they'll be thoughtful; they'll be interested," Hennes said.
Visitors will also be able to see faces for all 2,983 names inscribed on the bronze parapets of the memorial pools.
The museum won't ignore Osama bin Laden or the men who commandeered four passengers jets into the twin towers, the Pentagon in Virginia, and a field in Pennsylvania.
"Certainly, in this space no one will leave here without knowing who did this to us," Daniels said, including bin Laden, as the head of al Qaeda and the 19 hijackers that boarded those planes."
The museum and memorial cost $700 million to build, two-thirds of that collected in private donations and the rest in government funds. With foundation's operating costs expected to run $60 million a year, tickets to the museum could run $20 or more.
"We will have an admission charge for the museum -- not for the memorial at all or ever." Daniels said. "There's an excitement and an anticipation for us to finish, and we cannot wait to open our doors and welcome the world."