Coroner's finding - first blast fatal

Laurie Drew, left, father of one of the victims of the Pike River mine explosion, arrives at the Greymouth District Court for the coroner's inquest into the ddisaster. Photo / Simon Baker

All 29 men lost in the Pike River disaster died within minutes of an initial explosion at the West Coast coal mine, a coronial inquest has found.

Chief Coroner Neil MacLean found the Pike River miners would have died either from the impact of the blast or from the poisonous atmosphere it created in the mine.

Evidence showed those that survived the explosion would have lost consciousness and died from hypoxic hypoxia, or lack of oxygen, within minutes, he said.

He concluded all 29 men were dead, read their names to the court and said death certificates would be issued.

"The death of all 29 men occurred on the 19th of November either at the time of the very large explosion that occurred or a short time thereafter."

Mr MacLean delivered his findings and closed the coronial inquest into the Pike River disaster shortly after 2pm at the District Court in Greymouth.

He said his investigation of the disaster opened on the day of the initial explosion - after police notified his office that it was likely there had been violent or unnatural death at the mine.

It was known "at a very early stage" that it was unlikely bodies would ever be recovered from the mine and identified through DNA testing and other scientific procedures, he said.

"It was highly probable that the disaster victim identification type of procedure... was an unlikely scenario and that I should proceed down the track I have done today."

His timeline of the disaster stated that on November 19 at 3.44pm, CCTV coverage showed a sustained 50 second blast coming out of the Pike River mine portal.

At 3.50pm a power outage was noted by mine staff.

An electrician was sent down the mine to see what had gone wrong at 4.20pm, where he found the sprawled body of survivor Daniel Rockhouse next to his stalled juggernaut, before being forced to retreat by toxic gases.

Emergency services were notified there had been an explosion at 4:35pm.

Earlier, Mr MacLean said he had viewed footage taken from a borehole deep in the coal mine.

He said the footage, from a video camera and a Cavity Analysing Laser System (CALS), did not show whether the initial explosion was survivable or whether there were bodies in the mine.

Though that meant it would have no impact on his inquest, it would be of "significant interest" to a future Royal Commission of Inquiry into the disaster, he said.

Inquest 'heart-wrenching'

Speaking outside Greymouth District Court after the conclusion of the inquest, Bernie Monk, spokesman for the families and who lost his son Michael in the disaster, said although the families were prepared for what would be said during the inquest, it was still very difficult to hear.

"A lot of us cried and I'm still crying inside," he said. "But we'll handle it. It's part of the healing and we'll move on."

Hearing the names of the 29 dead read out did not get any easier, Mr Monk said. "I think it's comforting that we are all together and we are sticking together, and we really all helped each other through that period today."

Asked if the families had been given false hope of the men surviving the first explosion, Mr Monk declined to comment when the families' lawyer intervened and stated that would be an issue for a later time.

Peter Whittall, Pike River Coal chief executive, said it was heart-wrenching listening to some of the material at the inquest but it was important to get some closure in at least one stage.

"I don't think anyone will be able to hear the names of the men or see them written down without having some emotional reaction. It takes a long time to hear 29 names read out - just the sheer volume of them."

Mr Whittall denied the families were given false hope that the men could have survived the first explosion.

"Hope is what it is at the time. You can always analyse something in hindsight. I think at the time, certainly I can speak personally, I genuinely believed then and haven't changed my view that there was an opportunity to give hope to the fact that they might have survived the first blast, that they could have been holed up somewhere in the mine. Certainly that second blast put paid to that."

Whether the deaths occurred closer to the first or second explosions was really irrelevant, Mr Whittall said.

'Chance of survival nil'

Earlier in proceedings, Superintendent Gary Knowles told the inquiry today that expert evidence from Dr Robin Griffiths of the University of Otago showed the first blast on November 19 would have released a lethal combination of carbon monoxide and carbon dioxide.

All 29 miners would have died within five minutes, the inquiry heard.

"The chances they would have lived would have been nil.

"In the presence of such low oxygen hypoxic hypoxia would have occurred rapidly.

"They would have remained unconscious until death three to five minutes later."

Mr Knowles read out a list of all the miners and the last time they were seen before they died.

Many of the miners were last seen by family on November 19 - the morning of the explosion.

Tale of heroism

Mr Knowles told the court one of the men in the mine, Daniel Rockhouse was working about halfway into the mine when the blast happened.

Mr Rockhouse saw a "white flash", was blown off his feet, and was deafened by the noise.

The mine filled with smoke, Mr Knowles said.

He was able to put a gas mask on, but panicked and fell unconscious for about 20 minutes.

When Mr Rockhouse awoke he was able to get to an oxygen valve and also rang the mine base to alert them to the explosion.

"He made his way back out of the mine where he came across another miner, Russell Smith," Mr Knowles said.

Mr Smith was semi-conscious but unable to put a gas mask on, so Mr Rockhouse picked him up and dragged him further back down the mine shaft.

When Mr Smith was recovered enough he was able to walk by himself.

The pair kept stopping on their way back to check for light and any sign of life, but none could be seen, Mr Knowles said.

- with NZ Herald staff and NZPA