NEW YORK, USA (AP) — Eleven years after terrorists attacked the World Trade Centre, a new multibillion-dollar World Trade Centre once again dominates the lower Manhattan skyline. 

Hundreds of construction workers are at the 16-acre site every day, and tourists snap thousands of photos of the two towers that are nearing completion.

The status of the trade center's major components, according to developers:

• Most of the eight-acre memorial quadrangle at the World Trade Centre opened last year on the 10th anniversary of the attacks. Since then, some 4.5 million people have visited the memorial, with its twin reflecting pools where the towers stood. 

But a museum being built in a cavern beneath the plaza is still incomplete. Work all but stopped last fall because of a funding dispute between the memorial foundation and the Port Authority of New York and New Jersey. Joseph Daniels, president of the National September 11 Memorial and Museum, said that once construction resumes it will take more than a year to finish the job, meaning the museum might not open until 2014.

• One World Trade Centre, formerly known as the Freedom Tower, will open in 2014 on the northwest corner of the trade center site with three million square feet of office space. 

Tenants, so far, include magazine publisher Conde Nast and the federal government's General Services Administration. The spire atop the 104-story building will reach the symbolic height of 1,776 feet. There will be observation decks on the 100th, 101st and 102nd floors. The building without the spire has reached its full height of 1,368 feet. It is expected to cost US$3.9 billion by the time it is finished.

• The first office building to open will be the 72-story 4 World Trade Centre at the southeast corner of the site. It has reached its full height of 977 feet and is scheduled to open in October 2013. Tenants will include the Port Authority, the bistate agency that owns the trade center site and lost its headquarters when the twin towers were attacked.

• Just north of 4 World Trade Centre is 3 World Trade Centre, which is now an eight-story stub but will reach 80 stories and 1,150 feet when it's complete. Developer Larry Silverstein is required to lease at least 400,000 square feet of space before finishing the building. Silverstein's team is projecting a completion date of 2015 or 2016.

• At the site's northeast corner, 2 World Trade Centre is up only to street level. The building is planned as an 88-story skyscraper but will not be built until the commercial real estate market picks up enough to fill it.

• The new transportation hub at the trade centre will connect 13 subway lines and PATH trains to New Jersey when it opens in 2015. It will replace the temporary PATH station that was built after the September 11 attacks. Designed by Spanish architect Santiago Calatrava, the station will serve 250,000 travelers a day. There will be two levels of retail space. None of the tenants has been announced yet. The cost of the transportation hub, originally pegged at US$2.2 billion, is now expected to exceed US$3.5 billion.

• A performing arts centre planned for the site has been in limbo for years. A board of directors was named this year and was given the task of raising money to build the center, which is to include a 1,000-seat theater.

• An underground vehicle security centre and bus parking facility just south of the main trade center site will open in 2013.