They came in their thousands to the US embassy in Ballsbridge, Dublin, yesterday - Irish, American, Irish-American, German, Italian.
In the long queue to sign books of condolences were people who had visited the US; including those who had marvelled at the World Trade Centre and who had, like so many of us, bought souvenirs on its 107th-floor shop; people who had lived in the US and those who had never been there.
There was an outpouring of grief; people cried on each other's shoulders as they examined thousands of floral tributes from all over the country which lined the ground and railings outside the embassy. Children lit candles at the base of a small tree. The smell of lilies, the floral symbol of sorrow, was overpowering. There were wreaths - expensive wreaths in blue, white and red - with messages of sympathy and support from Donegal to Cork.
Other symbols of solidarity were tied to the railings - an NYPD baseball cap for the hundreds of New York police officers lost in the rubble of the World Trade Centre and those who continue to pull victims from the tangled mess.
An Irish pilot, who signed his name only as "D", had left his uniform stripes wrapped in clear plastic. His note remembered the crews of the crashed aircraft and extended sympathy to their colleagues and family members.
Pages and pages of handwritten tributes in a half dozen books of condolences noted the inadequacy of words to express feelings in the wake of such horror.
Ms Bernadette O'Connell, who has lived in Ireland for four years but is from Washington, was there with her baby Maureen and husband Aidan. She said she wanted to be at the embassy because she could not be at home. Her late father had once worked in the Pentagon.
Margaret and Alan Dixon from Blackrock were there with their children, Lianne and Andrew. They had attended a church service earlier. Mr Dixon remarked on "the insignificance of everything" in the face of this week's events.
Greg and Mary Begley from Rathmichael, Co Dublin, came with their children, Anna (7), Jane (6), Jessica (4) and Harry (11 months). "Since Tuesday, we have felt very sad as a family," said Mr Begley. "We were trying to explain to the children what's going on and we wanted to do something as a family."
Mr Aidan Minogue, originally from Roscrea, Co Tipperary, and his wife Jacqueline, from Dublin, moved back to Ireland three weeks ago after more than a decade in New York. Ms Minogue was tearful. "It's just beyond words." Their children, Gregory (2) and Magenta (4), were adopted in the US and they have many friends there, including in the fire services and NYPD. "We feel their pain," Ms Minogue added.
Mr Anthony Powers from Texas is living in Co Kildare but will eventually return to the US. He stood alone and clearly angry, but he was touched by the tributes at the embassy and by Ireland's decision to hold a day of mourning. "Right now I'm waiting to hear from four friends who were working in the World Trade Centre. I've called home - time seemed to stop - but they are missing. I feel so distant from my country in their time of need."
"We did not deserve this. We have tried our damnedest to make sure everybody around the world is happy, that everyone receives our shelter." Dealing with fanatics, those who had perpetrated these attacks, was like "throwing kerosene on a fire", Mr Powers said. But "they have woken a sleeping giant".