The man in charge of the investigation into the Gleision Colliery disaster has said that nothing more could have been done to establish what happened.
Speaking exclusively to ITV Cymru Wales for tonight's Wales This Week programme, the Acting Chief Inspector of Mines Steve Denton said he is satisfied that the Health and Safety Executive did everything it could.
That comes despite criticism, from the families of the four miners who died in September 2011, that they were not thorough enough - and a public inquiry is now needed.
There is much more on this story on:
Wales This Week, tonight at 10.35pm on ITV Cymru Wales
Y Byd Ar Bedwar, tonight at 9.30pm on S4C
More top news
It will become drier in the early hours setting us up for a fine start to Wednesday
Showers in the north will spread southeastwards overnight. Temperatures will be higher so not as chilly as list night.
Chilly start to Tuesday, turning into a largely fine and dry day.