Published Sunday, 11 September 2011
Almost 3,000 people were killed in the co-ordinated suicide attacks on the United States in 2001.
Two planes hijacked by Al Qaeda crashed into the twin towers of the World Trade Centre.
A third plane was directed into the US government's Pentagon building in Virginia while a fourth, United Airlines Flight 93, came down in a field in Pennsylvania after passengers attempted to retake control.
On Sunday Mayor Niall Ó Donnghaile was joined in the grounds of Belfast City Hall by US Consul General Kamala Lakhdhir, other dignitaries and families who lost loved ones in the attacks.
The crowds observed a minute's silence at 1.46pm - as people in New York were remembering the moment that American Airlines Flight 11 crashed into the north tower ten years ago.
Mayor Ó Donnghaile told the audience: "We are not strangers to the circumstances where a loved one leaves the house for work and never returns home again.
We share a common bond of hurt, of bewilderment, of loss between the people of New York, and across America, and Belfast.
Belfast Mayor Niall Ó Donnghaile
He told UTV: "It's a day of reflection for people right across the world, because there was no-one who wasn't touched by the scenes that we all witnessed on our television screens that day 10 years ago."
Flowers were laid at the commemorative stone on the lawn and the Belfast Community Gospel Choir performed a choral tribute.
A recorded message from the Fire Department of New York's Edward Kilduff was also broadcast to the crowd.
He paid tribute to the people of Belfast and to the emergency services in Northern Ireland for their support.
Consul General Kamala Lakhdhir delivered a letter from New York mayor Michael Bloomberg to the people of Belfast.
"Given how many of those we lost that day had connections to your land, it seems only fitting that the memorial stands just one block away from the Irish Hunger Memorial," the letter read.
"Together they will forever remind us of how indebted our city is to those who trace their roots to your shores."
He added: "I know we will find inspiration in their memories - and in the spirit of unity that brings Belfast and New York together once again today."
A live video feed showed TV footage from New York where US President Barack Obama and his predecessor George Bush attended a service at Ground Zero.