New York: US President Barack Obama and his predecessor and political rival George W Bush along with their wives led the world in mourning the loss of nearly 3,000 lives, exactly 10 years ago in the most fearful terror attack that irreversibly changed the way we live.

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Dressed in black, the two couples held hands as they walked slowly along the memorial, watching the wall etched with names of the 2,983 people killed in the terror unleashed by al-Qaeda chief Osama bin Laden.

Even though bin Laden was taken out in unilateral raid by American military commandos on May 2 in Pakistan, the wounds of the victims' families, including Indians, remained fresh.

The solemn event telecast live globally was under heavy security cover, following fresh security alerts regarding a possible al-Qaeda attack.

An eerie silence gripped the ground-zero as the America's first family -- Obama and Michelle along with Bush and his wife Laura spent about a minute at the 30-foot waterfalls that are part of the new memorial. Obama did not make any speech, but read a passage from the Bible.

Families held each other's hand as Obama read out verses from Psalm 46, which talks about God as a source of refuge and strength.

"God is our refuge and strength, a very present help in trouble. Therefore, we will not fear, even though the earth be removed and though the mountains be carried into the midst of the sea, though its waters roar and be troubled, though the mountains shake with its swelling," Obama read.

People silently held on to American flags as well as photos of their loved ones who died when hijacked twin planes rammed into the iconic World Trade Centre here, bringing the skyscrapers down like a pack of cards.

The ceremony began with a procession of bagpipers and singing of the national anthem by a choir.

In an emotional rendering, sons, daughters, wives and husbands read out names of all the 2,983 people who died in the attacks as family members wiped away tears, promising
"never to forget" what happened on the fateful September day and the service of the people who laid their lives to save others.

Mukul Agarwal and Bela Jagdshi Phukan were among the names that were read of the several Indian-Americans who had died in the attacks.

Mayor Michael R Bloomberg said that the attacks had turned "a perfect blue-sky morning" into "the blackest of nights." He added, "We can never unsee what happened here."

Incidentally, unlike earlier occasions, the ritual of reading the names of the dead took place against a backdrop of the spectacular, three-quarter-built 1 World Trade Center tower, rather than a construction site- ground-zero.

People also saw the dedication of a simple, but moving monument consisting of massive fountains, sunk into the footprints of the former towers, with the names of the dead written in bronze around the edges. People gathered and prayed at cathedrals in their cities and laid roses before fire stations.

Americans saw new memorials in lower Manhattan, rural Pennsylvania and other places.

Formal ceremonies were held in many countries to remember the souls of those killed.

Even though 10 years have passed since the tragic attack, the pain and the suffering still exists.

Indian origin surgeon John Mathai, who lost his younger brother Joseph, says 10 years may seem a long time to many but for him the years have not dulled the pain of the "unfortunate" event.

"The loss of my brother is a loss that will never be replaced. Ten years have gone by but there has hardly ever been a day where I have not thought of him and the wonderful
time we spent in New York," Mathai said.

New Jersey resident Arjan Mirpuri's 30-year-old son Rajesh was among victims. "My son did not even work at the World Trade Centre. He had gone there that day to attend a trade show. Before that day, Rajesh had never gone to the WTC. 9/11 became the most unfortunate day of our lives," Mirpuri said.

Artists Yo Yo Ma and James Taylor performed at the commemoration ceremony.

Moments of silence were observed at the exact times when the planes crashed in the Twin Towers, the Pentagon and in Pennsylvania.

The streets of New York wore a deserted look with only a few people on the sides of the roads.

George Bush also read from a letter Abraham Lincoln wrote to a civil war widow 150 years ago.