Nightmares about the 12 Queensland miners he could not save have haunted John Brady for more than 20 years.

The Royal Commission into the Pike River mine tragedy will be headed by High Court Judge Graham Panckhurst.

The Pike River Coal mine may have to be temporarily sealed after a fourth blast sent smoke and flames spewing from underground.

A royal commission of inquiry into the Pike River tragedy will look at causes of the blast and the initial response.

Jim O'Donnell helped drag his dead mates out of the Strongman mine in a marathon rescue.

Families grieving after the Pike River disaster have called on a lawyer who rallied for victims in a previous West Coast disaster.

The Prime Minister and Governor-General will speak at a memorial for the 29 men who died in the Pike River Coal mine.

The Pike River blast has led some miners to discuss whether it is safe to remain in the industry.

Leigh Hart, aka That Guy, shares a very personal account of how mining disasters can affect families.

An NZ Mines Rescue member wants the public to understand what the rescue team members are going through.

Broadcaster Maggie Barry, whose cousin Michael Monk was lost at the Pike River mine, understands when people asked counsellors "funny" questions.

"What gave armchair critics the right to criticise and worse - accuse the rescuers of deliberately sitting on their hands?"

Up to 500 relatives and friends of the Pike River miners travelled to the mine today, which one mother described as "very healing".

"We pray that their moment of fear becomes eternal peace," said Monsignor Gerry O'Connor during an emotional tribute to the Pike River miners in Greymouth.

Families of the dead men due to be bused to the Pike River mine tomorrow will still go, despite a third explosion at the mine this afternoon.

A Westport man has told how he and three others ran for their lives when the Pike River Coal mine exploded at 2.37pm on Wednesday.

There has been a third explosion at the Pike River mine this afternoon. The blast occurred at 3.39pm and lasted for 23 seconds.

A third robot that has gone 1575m into the Pike River coal mine has detected debris and destruction indicating Wednesday's blast was much more violent than the first one.

It is likely to be several more days before operations will start to stabilise the Pike River mine so that the bodies of 29 men can recovered, police say.

A Pike River Relief Fund Trust has been established for the families of the 29 men who died in the Pike River coal mine.

A small West Coast community will now face the task of recovering and rebuilding following a disaster of devastating proportions.

International experts say they are shocked a mining disaster the magnitude of the Pike River tragedy occurred in a modern mine.