The Bloody Sunday killings were unjustified and unjustifiable, the Prime Minster has said.
Thirteen marchers were shot dead on 30 January 1972 in Londonderry when British paratroopers opened fire on crowds at a civil rights demonstration.
Fourteen others were wounded, one later died. The Saville Report is heavily critical of the Army and found that soldiers fired the first shot.
Prime Minister David Cameron said he was "deeply sorry".
He said that the findings of the Saville Report were "shocking".
The Prime Minister said:
No warning had been given to any civilians before the soldiers opened fire
None of the soldiers fired in response to attacks by petrol bombers or stone throwers
Some of those killed or injured were clearly fleeing or going to help those injured or dying
None of the casualties was posing a threat or doing anything that would justify their shooting
Many of the soldiers lied about their actions
The events of Bloody Sunday were not premeditated
Northern Ireland's Deputy First Minister Martin McGuinness, Sinn Fein, was present at the time of the violence and "probably armed with a sub-machine gun" but did not engage in "any activity that provided any of the soldiers with any justification for opening fire"
The report was commissioned in 1998 by the then Prime Minister Tony Blair under the auspices of former High Court judge, Lord Saville of Newdigate.
The Saville Inquiry took witness statements from hundreds of people and has become the longest-running and most expensive in British history.
It closed in 2004 with the report initially due for publication the following year.
It cost £195m and took 12 years to complete.
According to BBC NI political editor Mark Devenport, while it may not have been the bloodiest day in the history of the Troubles, "the significance of that day in shaping the course of the conflict cannot be overstated".
"The actions of the Parachute Regiment in shooting dead 13 unarmed civil rights protesters immeasurably strengthened Irish republicans' arguments within their own community and provided the Provisional IRA with a flood of fresh recruits for its long war," he said.
Good that it only took £195m and 38 years to figure out what the rest of the world has known for decades. If Brits wonder why the IRA had such a sympathetic ear in the rest of the world, they can start right here. There were atrocities on both sides, no doubt. But this one event fuelled the escalation of violence like no other, and irreparably damaged the prospect of peace for decades to come.
"Hang on while I log in to the James Webb telescope to search the known universe for who the fuck asked you." -- James Fell
I have to agree Scoot, I wonder if we'd have had the bombings and massacres all over the UK if this hadn't escalated the troubles.
“If you trust in yourself, and believe in your dreams, and follow your star. . . you'll still get beaten by people who spent their time working hard and learning things and weren't so lazy.”