Prince Harry bowed his head in prayer at the site of the Sept. 11 terrorist attacks on Friday "in admiration of the courage shown by the people of this great city," as he wrote on a wreath he placed at the site of the destroyed World Trade Center.

The 24-year-old prince — famed for his youthful, at times embarrassing, escapades — is on his first official trip to the United States.

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Clearly, Harry had a different agenda as he started his two-day New York visit.

Dressed somberly in a blue suit, red-and-blue striped tie and black toe-cap shoes, he arrived at the site just after noon.

Harry was greeted by New York Gov. David Paterson and Christopher Ward, executive director of the Port Authority of New York and New Jersey, which owns the site. The prince then spent about 15 minutes quietly speaking to a half-dozen relatives of victims of the attacks.

Among them was Chip Callori, whose brother, Joseph Amatuccio, was killed on Sept. 11, 2001. "It's a very kind gesture on his part — for him to realize that this is a sad but important part of our history," said Callori.

On a chain-link fence overlooking the Sept. 11 memorial under construction, Harry attached a wreath of peonies and white and yellow roses. Standing alone, he bowed his head in silence for a few minutes.

A handwritten note on the wreath read: "In respectful memory of those who lost their lives on Sept. 11, 2001, and in admiration of the courage shown by the people of this great city on that day." It was signed, "Harry."

Harry walked along the southern perimeter of the 16-acre (6.5-hectare) site, stopping to pore over rebuilding plans two officials showed him.

"Big question — when is this supposed to be finished?" asked the prince, who peppered officials with questions about the construction.

Officials of the Port Authority of New York and New Jersey have projected finishing dates for the memorial, a skyscraper and a transit hub between 2011 and 2014 but have no completion dates for four other office towers.

As he left the site, he added, "It's just fantastic to see what's going on and hopefully everyone will be happy with the results — I'm sure they will be."

At the firehouse across the street that houses Engine 10 and Ladder 10, which lost five members on Sept. 11, the prince shook hands with firefighters, then stepped in to admire their equipment as they talked and laughed.

Back on the street, Harry suddenly broke away from his security detail and turned the corner to see the side of the firehouse, which is graced by a bronze memorial to 343 firefighters killed at ground zero.

A few feet away, hundreds of people behind police barricades strained for a glimpse of smiling, red-haired Harry. His fun-loving, outgoing nature erupted as he strolled over to shake hands and chat.

Maria Jimenez, a tourist from Texas, rushed over to snap pictures, saying, "I'm very excited. We don't get very many opportunities to see a prince in Houston, Texas."

The younger son of Prince Charles and the late Princess Diana is third in line to the British throne, after his father and older brother, William.

Early Friday afternoon, Harry formally named the British Memorial Garden in Hanover Square downtown to honor the 67 British victims of the terrorist attack. On its wrought-iron fence, 67 finials are to be painted gold in honor of the British victims. Harry helped plant a so-called "Elizabeth" magnolia tree as part of a New York program to plant 1 million trees in the city.

His father, Prince Charles, and stepmother, Camilla, dedicated the center stone of the garden in 2005 during their New York visit.

Later in the afternoon, Harry visited Manhattan's Veterans Affairs Medical Center, where he was greeted with loud applause and toured a clinic that treats veterans with post-traumatic stress disorder and its prosthetics facilities.

He shook hands with Paul Yarbrough, a double amputee with two prosthetic arms, and jokingly pretended his grip was too tight, crying out in pain. He then watched the 42-year-old Gulf War veteran pick up a bottle of orange Snapple and drink it.

Joining the prince there was a 21-year-old British soldier who lost both legs when he stepped on an anti-tank mine in Afghanistan last year, while Harry was commanding troops nearby.

Dubbed "the party prince," Harry is a much-watched member of the royal family, regularly making newspaper headlines with his romantic escapades and brushes with scandal. Several years ago, he apologized for wearing a Nazi swastika armband to a friend's costume party.

His New York fun is to come on Saturday, when the prince is to participate in the Veuve Clicquot Manhattan Polo Classic on Governors Island in New York Harbor, facing off against Argentinian polo player and heartthrob Nacho Figueras.

On Friday, Harry seemed to already have captured New Yorkers' hearts.

As he headed for his motorcade near ground zero, the crowd waved, shouting "Bye, Harry!"