From Tokyo to Sydney, the world came together with the United States to mourn the loss of nearly 3,000 people, who lost their lives exactly 10 years ago in the most fearful terror attack that changed the way we live.
Formal ceremonies are planned or are already underway in many countries to remember the souls of those killed when hijacked twin plane's rammed into the iconic World Trade Centre in New York, bringing the skyscrapers down like a pack of cards.
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 told PTI.
And it is not that the threat of a terror attack has decreased since then. Even as the world pauses to reflect on the tragedy that killed 2,977 people from more than 90 countries, the city and Washington is under intense security gaze over yet another possible Al Qaeda attack.
In the first of the global memorials, the US rugby team attended an emotional service in New Zealand, hours ahead of their opening World Cup match against Ireland.
The US ambassador to New Zealand David Huebner said at the ceremony that 9/11 was a day "to commemorate the triumph of the human spirit", a rare day "that galvanised the collective hearts and minds of humanity".
Australian Foreign Minister Kevin Rudd and his French counterpart Alain Juppe, laid a wreath to honour those who have fought for freedom at the Australian War Memorial in Canberra. Rudd said another September 11-style attack could occur if nations drop their guard against terrorism.
"The thing about September 11 is it could have easily as happened in Paris, it could have easily as happened in Sydney," Rudd said adding, "And it still could happen. That is why the price of freedom is eternal vigilance."
In Japan, families gathered in Tokyo to pay their respects to the 23 Fuji Bank employees, who were killed in the attack. A dozen of the workers were Japanese.
South Korea's President Lee Myung-bak sent a letter to US President Barack Obama, conveying his "deepest condolences" to the victims of the 9/11 tragedy, their bereaved families and the American public.
Pakistan, which is under pressure to uproot terror safe havens from its soil, pledged to strengthen international cooperation to eliminate terrorism and asked the world community to uphold ideals like tolerance.
In the US, people gathered today to pray at cathedrals in their cities and to lay roses before fire stations. Americans will see new memorials in lower Manhattan, rural Pennsylvania and other places.
But unlike earlier occasions, the ritual of reading the names of the dead will take place against a backdrop of the spectacular, three-quarter-built 1 World Trade Center tower, rather than a construction site- ground-zero.
Sunday will also see 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.
Meanwhile, officials in New York and Washington have stepped up security for the 9/11 memorial services after a tip off that three Al Qaeda members could be planning to set off a car bomb in one of the cities.
Officials have however found no evidence of any terrorists sneaking into the country.
Summoning America to unity and service, President Barack Obama had Saturday paid tribute to its resilience and the sacrifice of its war dead.
A day before the anniversary commemorations, the president made a pilgrimage to Arlington National Cemetery, strolling with his wife, Michelle, among graves filled with dead from the Afghanistan and Iraq wars.
In an email to supporters, the president urged others to follow his lead. "With just a small act of service, or a simple act of kindness towards others, you can both honour those we lost and those who serve us still, and help us recapture the spirit of generosity and compassion that followed 9/11," the president wrote.
Image: A construction worker arrives for work at the World Trade Center construction site in New York