The apology came as the government released a long-awaited report on the so-called "Bloody Sunday" attack by British soldiers in Londonderry, which set off decades of violence between Catholics and Protestants and claimed nearly 4,000 lives, CBS News Correspondent Mark Phillips reports.
The march that January day 38 years ago began like many others of Northern Ireland's so-called "troubles:" a large crowd of Catholic nationalist marchers, a standoff with British soldiers, the first projectiles being thrown.
It was an ugly time and what happened next would make it worse.
The army opened fire. Thirteen civilians were killed that day. Another died from wounds later. Fourteen more were wounded. The army claimed it had been fired on first. What came to be known as Bloody Sunday became the best recruiting video the Irish Republican Army ever had.
On Tuesday, the victims' families got what they waited for so long, vindication.
"My brother, William, we know he was innocent," one family member said at a rally. "We've always known. Now the world knows."
They had not been armed. They had not posed a threat. The army had lied.
"What happened on Bloody Sunday was both unjustified and unjustifiable," said British Prime Minister David Cameron. "It was wrong."
The inquiry won't make it right, but it does absolve those who had demanded it.
Twenty-five minutes of mayhem. Thirty-eight years of waiting. And the story of Bloody Sunday isn't over. Apologies are one thing; prosecutions are another. Now the demand is for justice.