Superintendent Gary Knowles first broke the news to the families of the missing men before revealing the second “massive” explosion occurred at 2:37pm (NZDT) to local media and television crews.

“It is our belief that no one has survived and everyone has perished,” he said.

The exact cause of both of the underground gas explosions has not yet been determined.

But Pike River chief executive Peter Whittall said he was confident the second explosion was not triggered by actions of the rescue team, according to 3 News.

He reportedly said gas samples from the borehole finished this morning estimated the underground atmosphere to be 95% methane.

Mine safety expert David Feickert told TVNZ the second explosion might have been caused by smouldering material in the mine as samples today had revealed “some kind of heating was going on”

The second explosion confirmed that rescuers made the right decision to not risk more lives by entering the mine since disaster struck almost a week ago.

But two army landmine disposal robots were sent into the main access tunnel and, while they were risk assessed, they were not rated as intrinsically safe or flame-proof, a process which can take many months.

The tunnel inspection vehicle provided by Western Australia’s Water Corporation was reportedly still being prepared to make the journey into the mine when the second explosion occurred.

While the mine might eventually be sealed at the surface, Whittall told reporters the families will still want the men back even if they are no longer alive.

The Pike River miners are instructed to walk out of the mine using breathing apparatus under emergency procedures, with only two miners emerging after the first explosion took place on Friday.

Two Australians, Joshua Ufer and William Joynson, are among the 29 miners feared dead.

Recovery operation

With the missing miners believed to be dead following the second, bigger explosion, a recovery operation to retrieve the bodies is being formulated.

Methane levels remain an issue and QMRS has sent over its GAG inertisation unit, basically a jet engine, to solve this problem.

The unit shoots out large volumes of nitrogen, carbon dioxide and some water.

It could not be used before as it would have killed any possible survivors.

Trauma expert on Pike River

A memorial service was held in Greymouth last night with more expected in the next few days.

University of Western Sydney School of Medicine professor Beverley Raphael delved into what some of the families might be thinking.

“The explosion, the toxic nature of the gases, particularly the prolonged period, will influence how family members imagine the way their loved ones have died," she said.

A lot of the mainstream media reporters were overly influenced by the miracle mine rescue in Chile, even though this was a hard rock mine with completely different circumstances to the Pike River mine disaster.

The Pike tragedy shared more in common with the Upper Big Branch mine explosion in April, with US authorities and Massey Energy management still at odds in the subsequent investigations.

Raphael also discussed the “Chile miracle effect”

"The almost magical rescue of people in other countries doesn't help,” she said.

“In New Zealand many of the family members will be asking themselves 'why couldn't that happen here? Why couldn't my loved one have been saved?'"

She added it was important that people stay in touch with the Greymouth community with “the real grief and pain to come over time”

The expert added that family members of the lost miners might need practical support too.

“What was recommended after the London bombings was a family liaison officer who would cut through the bureaucracy on issues and touch base with the family regularly,” she said.

"The support needs to be there for them, but it shouldn't be forced on them."