Changed View at Grand Zero

Visitors to ground zero on the sixth anniversary of the terror attacks today will find a changed landscape at the former location of the World Trade Center.

Hundreds of thousands of people come to the site each year, but last year they would have seen an empty construction site. Today it's a hive of activity.

"Oh, it feels wonderful. It only took us 5½ years to get there," developer Larry Silverstein told ABC News' Dan Harris.

Watch Dan Harris' report tonight on "World News with Charles Gibson" at 6:30 EDT.

Silverstein signed a lease on the World Trade Center six weeks before Sept. 11 and was at the center of an epic New York battle over rebuilding.

After a swift and valiant rescue and cleanup at ground zero, politicians, businessmen and victims' family members fought over who would build what and where.

"It was excruciating, frustrating and difficult," Silverstein said.

"There's enormous emotional content," said Tony Shorris, executive director of the Port Authority of New York and New Jersey. "And they're New Yorkers and they're pretty good at arguing on a good day."

Site Progresses, but Controversy Persists

Last year, shortly after Sept. 11, the major parties struck a deal and freed up $16 billion for six massive projects planned to cover the 16 acres of land.

They include the Freedom Tower, which is planned to rise to 1,776 feet, making it the tallest building in the country. It will share the space with a trio of commercial high-rise buildings, a train station with a roof designed as a pair of wings to open every year on Sept. 11 and a memorial with 400 trees and two huge reflecting pools.

There is still controversy, however.

Some family members feel that all 16 acres should be treated as hallowed ground. Monica Iken, who lost her husband, Michael, when the towers were destroyed, is among them.

"I wasn't able to take Michael home and I don't think people understand what that feels like to see buildings going up," she said.

And, architectural critics say developers failed to reimagine the skyline.

"I think ground zero was an opportunity lost," said New Yorker Paul Goldberger. "I think people meant well, but there really isn't going to be anything terribly special there."

The developers say that by 2012, when everything is built, Americans will be proud.

"I do believe they will find this to be a spectacular execution," Silverstein said.