The families of four miners killed in the Gleision colliery disaster say they are still waiting for answers about what happened.
Charles Breslin, Philip Hill, Garry Jenkins and David Powell died when the Swansea Valley mine flooded.
A year on, their families have spoken about their pain at discovering the men had died and their ongoing grief.
Police investigating the incident say they have handed a file to the Crown Prosecution Service (CPS).
In a special BBC Wales Week In Week Out programme, the miners' relatives say they still do not know exactly how and why the men died.
Hayley Phillips, the niece of 45-year-old Mr Hill, said: "At the moment there are still so many unanswered questions of how this possibly could have happened and ruin four lives and four families."
Mine manager Malcolm Fyfield was seriously injured in the incident but escaped through an old mine shaft.
Two other miners, including Mr Powell's son, escaped and helped raise the alarm.
As rescuers tried to reach the four trapped men - all experienced miners - their families gathered at the nearby Rhos Community Centre where a team of liaison officers from South Wales Police kept them updated.
The country also watched and waited as news of the disaster unfolded on a hillside above the village of Godregraig.
Coming just weeks after the rescue of the Chilean miners, there was genuine hope that the four men would be found alive.
The families have now revealed the agony of waiting for news, and of their hope fading when the first body was discovered but not identified.
Ms Phillips said she vividly remembered the moment a police officer told the families the news.
"I can still see his face. He took his hat off and he held it by there and he said, 'Can I have your attention'," she said.
"And he closed the doors and he closed the windows, and he looked at us and he said, 'There's no way I can say this other than I'm really sorry but we've found a body'.
"And the whole place just collapsed."
Mr Breslin, 62, was just two months off retirement. His wife Mavis was convinced all along that he would get out alive.
"In the car on the way down, all I did was pray," she said.
"I thought I don't care if he's paralysed, as long as I can have him home. But no."
David Powell's widow Lynette said she would never come to terms with what happened to her husband, who had just turned 50.
"The love of my life I have lost forever," she said.
"And I don't know how to cope. I know it's a year and I should be coping but it's getting worse.
"I know they say I was supposed to get better but it's getting worse, not better."
Thousands attended the men's funerals.
Alex Jenkins, whose 39-year-old father Garry was the first to be found dead, wanted to pay his own special tribute to his dad.
"I asked the undertaker if I could walk the coffin to the grave, because dad was there when I came into the world so I thought I'd be there when he gets taken out," he added.
South Wales Police launched an investigation into the incident, led by Det Ch Insp Dorian Lloyd.
He said a file had been given to the CPS which was currently considering the evidence.
The mine's manager Malcolm Fyfield has been questioned on suspicion of causing manslaughter through gross negligence.
The privately-run mine has been closed and its licence has been suspended.
A memorial fund led by Prince Charles has raised more than £1m for the families.
Gleision: A Year On - The Families' Stories, Week In Week Out Special is on BBC One Wales, at 20:30 BST on Monday, 17 September.