Workplaces, schools and shops were silent. Churches and cathedrals overflowed. Throughout the island yesterday millions remembered the victims of what the President, Mrs McAleese, called "these awful acts of hatred".
North and South, city streets, public spaces and private homes fell quiet at 11 a.m. in an unprecedented show of solidarity with the United States and the families of the thousands lying dead under tonnes of rubble in New York and Washington.
The three minutes of silence were observed at the same moment throughout the EU, although in other member-states, work continued as usual. In Ireland alone yesterday was a "public holiday", but it was treated throughout the State as the day of mourning it was intended to be.
Tens of thousands of adults and children of all ages packed places of worship throughout the State. The 2,000-member congregation at St John's Cathedral in Limerick included many Americans stranded in Ireland since flights to the US were grounded on Tuesday. In cathedral, mosque and synagogue, the message from religious leaders was similar. We must pray for the victims and their families and show solidarity with the United States.
The most poignant prayers were for the families, including many in Ireland, still awaiting and dreading news of loved ones. "We feel so powerless in the face of this man-made carnage" said the Bishop of Galway, Dr James McLoughlin, but prayer would bring strength, he said.
Mrs McAleese said the day "sends a message across the Atlantic and indeed around the globe that Ireland too is broken-hearted and grieving deeply at the unconscionable waste of life we have witnessed this week".
The State's political, civic and religious leaders as well as the diplomatic corps attended the ecumenical service at Dublin's pro-Cathedral. Hundreds of people who could not fit inside stood quietly in Marlborough Street. Elderly women stood alongside teenagers with rings in their ears, lips or noses.
They applauded the President, and later, the Taoiseach, Mr Ahern, with his partner, Ms Celia Larkin. It was a moment when people needed to express faith in their political leaders. They applauded again for representatives of Dublin Fire Brigade, who poignantly brought to mind their exhausted counterparts in New York and Washington, mourning colleagues as they continued their grim work.
There were poignant moments throughout the island. In Derry, which has seen its own days of terrible sadness, many people wept as the Guildhall clock chimed to mark the start of the three-minute tribute. Bus drivers, taxi drivers and other motorists got out of their vehicles and stood with heads bowed.
In the Republic, Government offices and almost all businesses and shops closed for the day. All pubs closed during the daytime yesterday with some reopening for the evening. There were religious services at Dublin's synagogue and mosque. At Dublin's synagogue, the new atmosphere brought about by Tuesday's events was evident. Garda∅ stood at the door and gateway and plainclothes security men carried out discreet checks on every unfamiliar visitor.
At Dublin's mosque, there was condemnation of the attacks too. Mr Imam Hussein Halawa made Tuesday's events the focus of his speech at the weekly prayer, condemning "this horrible terrorist act which took place in America". However, he warned against "groundless accusations" being levelled against the Islamic religion.
Queues continued throughout the day at the US Embassy in Ballsbridge as thousands came to sign the book of condolences. At one stage, an estimated 6,000 waited patiently. Pages and pages of six separate books have been filled with some 30,000 personal tributes.
People cried on each other's shoulders as they read the cards attached to thousands of floral tributes which lined the ground and railings outside. Children lit candles at the base of a small tree. The smell of lilies, the floral symbol of sorrow, was overpowering. Among the carefully selected items of tribute was an NYPD baseball cap, and uniform stripes wrapped in clear plastic left by an Irish pilot who signed his name as "D".
Amid the expressions of grief and sympathy, Mrs McAleese also expressed hope for what will happen next. "May all leaders be directed by God's spirit so that justice and mercy may prevail in our world . . . May evil be averted and harmony restored."