Hopes of recovering bodies are fast fading for families of the 29 miners lost in the Pike River mine.

An Australian expert was arriving in Greymouth tonight to provide advice on the jet engine GAG operation at the ill-fated Pike River Coal mine, where it's "highly likely" part of a coal seam has caught fire.

The chief executive of Pike River mine says the families of the 29 victims of the disaster are coming to terms with the fact they may not get their loved ones back, as recovery efforts continue to be hindered.

Volunteers have been working "frantically" to prepare for Thursday's remembrance service to honour the 29 men who lost their lives in the Pike River Coal mine

Deployment of the "GAG" unit at the Pike River coal mine has been delayed after a fire at the entrance to the mine this morning. Rescuers are trying to extinguish a coal fire so the bodies of 29 trapped men can be recovered.

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.

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.

Another explosion shortly before 2pm today damaged some of the infrastructure at Pike River mine, but a "gagging" operation is still on track to commence tomorrow.

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.

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

Grey District Mayor Tony Kokshoorn wants the mining industry to learn from past mistakes and has called for a royal inquiry.

"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.