The first phase of rebuilding on the 16 acres of Lower Manhattan leveled by the Sept. 11 attacks began yesterday with a ceremonial groundbreaking for a new $2.2 billion transportation hub, highlighted by the release of two doves representing "peace and rebirth."

Five days before the four-year anniversary of the 2001 terrorist attacks, federal and state officials celebrated the first phase of reconstruction at a site still considered a cemetery by survivors.

"Today, we begin to take back a site and restore something that was taken away from us on September 11," said Anthony Coscia, chairman of the Port Authority of New York and New Jersey, which owns the site.

The transportation hub, designed by Spanish architect Santiago Calatrava, will link commuter trains from New Jersey, ferries and the city subway system. Officials estimate 250,000 people a day will stream through the transportation hub after its scheduled completion in 2009.

"New York is taking off again and set to soar to greater heights than ever before," said U.S. Transportation Secretary Norman Y. Mineta, speaking in the 70-foot pit where the city's tallest buildings once stood.

The transportation hub is being financed by federal grants of $1.9 billion and by $300 million raised by the Port Authority. In the next six months, a total of $10 billion in new construction will get underway, said Mayor Michael R. Bloomberg (R). The planned projects include an underground memorial and the 1,776-foot Freedom Tower.

Construction of the transportation hub will begin next week. Families of Sept. 11 victims requested that the building's footprints remain uncovered for a 9/11 commemoration ceremony planned for the weekend, said Steve Coleman, a spokesman for the Port Authority. Workers will then lay a protective cover on the steel footings of the twin towers.

The design and intent of the rebuilding effort have been a focus of conflict and controversy. Some families of Sept. 11 victims waged a campaign against two museums planned for a new cultural center, charging they planned to host exhibits critical of the U.S. government.

Some officials at the ceremony drew parallels between the task of rebuilding the World Trade Center site and the challenges facing the Gulf Coast in the aftermath of Hurricane Katrina.

"Let what we are doing be a beacon to the people of New Orleans," said Sen. Charles E. Schumer (D-N.Y.). "They should always know there is always hope, hope that is represented today by the rebuilding."

N.Y. Gov. George E. Pataki (R) speaks during the ceremony to break ground for

a $2.2 billion transportation hub on the site of the World Trade Center.