Fresh inquests are to be held into the deaths of 21 people in the Birmingham pub bombings after evidence emerged the police may have ignored tip-offs about the attacks.
The senior coroner for Birmingham and Solihull Louise Hunt announced the decision after holding several review hearings and receiving "significant" new information about the double bombing on November 21 1974.
During recent hearings, families of some of those killed in the blasts in the Mulberry Bush and Tavern In The Town pubs put forward a claim that the British state had knowledge of the attacks planned by the IRA before they were carried out.
The coroner found the families' claim that police had been protecting a mole in the IRA cell was unfounded, and neither did the emergency services' response that night contribute to the deaths.
But setting out the reasons for her ruling, Ms Hunt said there was evidence that West Midlands Police had missed two potential warnings of the bomb attacks, including a comment made by men linked to the IRA that "Birmingham would be hit next week".
That overheard conversation was reported to police on November 10 1974, but Ms Hunt said there was "no indication that the police took any active steps in response to it".
On the day of the attack, a second tip-off by a source identified in court only as "Witness B" to the police was also not followed up, she added.
That person is believed to be the source of what the coroner described as "significant" new information during a review hearing, last month.
Ms Hunt today said: "I am unable to exclude the possibility that this was a second missed opportunity to prevent the attacks."
The coroner added: "I have serious concerns that advanced notice of the bombs may have been available to the police and that they failed to take the necessary steps to protect life."
Concluding, Ms Hunt went on: "This is specifically in respect of the two matters I have identified.
"It is only in respect of that issue that I consider there is sufficient reason to resume an inquest to investigate the circumstances of these deaths.
"So I am satisfied that the inquest should be resumed."
The pub bombings, widely acknowledged to be the work of the IRA, left 222 injured and led to one of Britain's worst miscarriages of justice in the convictions of the Birmingham Six.
Speaking outside the coroner's court, one of the men released in 1991 Paddy Hill welcomed the ruling.
He said: "We'll never get justice but I tell you one thing that we can get and that's the one thing we deserve the most - the truth.
"It's not so much me, I know the truth, I want this for the families.
"They've had their whole worlds collapsed twice, once when we got convicted and they had something to focus on - thought we'd got the guilty people in prison.
"Then we get released and ever since, they've been fighting for this for 20 years."
He went on: "I've known the truth all along. It's about time the British public knew the truth."
But Mr Hill said he was "sceptical" the truth would actually emerge.
"Birmingham police couldn't spell the word truth. They're rotten," he told reporters.
Julie Hambleton, whose 18-year-old sister Maxine was among the victims, welcomed the decision, saying it was "way beyond our expectations" as she urged the Government to ensure victims' families were given legal aid.
Her voice trembling with emotion, Ms Hambleton said: "This is the most seismic day for all of us
"I hope that our fathers, brothers, sisters, mothers are looking down and they're proud."
She added: "Our loved ones did not ask to be murdered that night.
"All we want is to be heard so we can get the truth, justice and accountability."
Ms Hambleton also called for the original bombers to "come forward, do the right thing".
Former West Midlands Police officer Bill Craig, whose 34-year-old brother James died in the attacks, said he believed the pub bombings investigation would be "another Hillsborough".
He said: "It's very complex, and it'll be a long process, but in the end this will end up as another Hillsborough."
West Midlands Police's barristers had objected in principle to the resumption of the inquests, arguing the coroner neither had the powers nor the "evidential basis" to order fresh inquests.
However, speaking after the ruling, Chief Constable Dave Thompson said in a statement: "I understand the families of those who lost their lives are frustrated, disappointed and angry."
He added: "I hope the new inquest provides answers to families."
Ms Hambleton said: "Do you know what the motto of West Midlands is? Forward in unity.
"Unity for whom?
"Because the senior management of West Midlands Police are not working in unity with the victims of the Birmingham pub bombings."
The coroner will now hold a pre-inquest review some time later this year.