The horror of that black weekend was so bad that Northern Ireland was plunged into despair: there seemed no end to the cycle of violence, no realistic hope of a more peaceful future.
It was clear from the moment of the explosion that this was a bad bombing, as the whole building collapsed in a pile of rubble. But each hourly news bulletin seemed to bring worse reports as the rescue operation proceeded: three dead; six dead; eight dead; 10 dead. And so many of the bodies unearthed in the rubble were those of women and children.
The IRA said its target was loyalist offices on the first floor, but the bomb, placed in a popular shop at a busy Saturday lunchtime, was bound to cause random civilian casualties.
For years Sinn Fein and its leader Gerry Adams had been professing a republican desire for peace, and a talks process was under way. But how could that be reconciled with an atrocity like this? When Mr Adams carried the coffin of Thomas Begley, the bomber, the republican position was condemned as hollow and hypocritical.
Most immediately, the air was filled not just with political despair but also with physical fear. Loyalist retaliation for the attack came quickly, killing another dozen people in revenge, seven of them in a Catholic pub at Greysteel, Co Londonderry.
All over Northern Ireland social functions were cancelled as people stayed indoors and took extra security precautions. One observer said at the time: "I really don't come across anyone now who doesn't talk about how dreadful it is. You can see the fear everywhere.
"At Mass on Sunday the priest said that police advice was for us to leave quickly, not to congregate chatting, just to get into our cars and get going."
Yet somehow the peace process survived that bleakest of moments, and that spasm of awful violence even became, in some mysterious way, a catalyst for progress. The momentum of peace picked up again and became even more determined; it was as if a community had peered over the brink of chaos, and backed away from it.
The Downing Street declaration followed in December 1993, and less than a year later both republicans and loyalists laid down their arms to bring the hope that a new era of peace could be created.
That hope is still alive; the pity is that the peace came too late for the victims of the Shankill bombing, and the other victims of the Troubles.Reuse content