Yet good will come if lessons are learned - leading to better mine safety rules and procedures, more rigorous regulatory oversight and resourcing and improved emergency response. That much is clear from the testimony so far.
Were project economics and the company's expectations an issue?
Development costs had blown out from an estimated $29.3 million in May 1995 to $350m by mid-2010 and production was well below target. Testimony suggests miners were under pressure to increase production and safety issues were given lesser priority.
The company's expectations of the mine, its research and experience were questioned at the start of the inquiry by Don Elder, chief executive of state-owned Solid Energy, an experienced West Coast mine operator. Elder claimed Pike had inadequate knowledge of its coal seam and relied on overseas consultants with little knowledge of the West Coast's complex geology. "Fundamentally, this is all about the geology."
Potential safety risks arose from the difficult geological conditions, the [hydraulic] mining method and prolonged financial pressure because of years of production delays.
Whittall has disputed that delays and finances had any impact on operating safety.
What safety challenges did geology and the mining method present?
Pike was known as a "gassy" mine. Methane could leak into gaps in the unstable Hawera Fault, near the coal seam, and the presence of sandstone raised the risk that trapped methane pockets could be released by drilling.
Coal was to be extracted using hydraulic equipment - water blasted at very high pressure to carve coal from the seam. But this has the potential to release large volumes of methane.
Hydraulic extraction was still in the commissioning phase, but there was a cluster of methane spikes in October.
This week, hydro-mining expert Masaoki Nishioka said Pike began hydro-mining in an unsafe place in the mine. The method of sealing off the goaf (the cavity left after coal is extracted), meant a "huge methane gas pocket" could be left. (The commission believes the goaf was the most likely source of methane that fuelled the explosion).
Nishioka feared the mine would explode at any time, but management was pushing to increase production. He said he told Whittall and mine manager Doug White to "not send anybody underground" until a robust ventilation system was in place and a second escapeway provided. When he tried to find out about ventilation, he was brushed off. He was relieved to leave at the end of his three-month contract in October.
Lawyers for Whittall and White say both deny they were warned the miners were in danger.
What might have caused the gas to ignite?
There is a risk of spontaneous combustion with different types of coal. An underground ventilation fan has been identified as a potential ignition source. Mine consultant David Stewart said there had been previous "frictional ignition" incidents, caused by sparks from the road header machine hitting quartzite sandstone. Another risk was miners smoking - a cigarette lighter and butts had been found in the mine.
How did the company address the geological and gas risks?
Geologist Jane Newman raised concerns about the company's lack of geological research. She was not confident the company understood there was sandstone within the coal seam near where the miners were working. She recommended extra drillholes, research and training but these were not enacted due to finances.
Solid Energy's underground mines manager Craig Smith said complex ventilation design was needed to manage methane but the company was trying to extract coal without fully understanding the conditions or investing in necessary equipment.
Former chief mines inspector Harry Bell, whose nephew Allan Dixon died in the mine, was engaged there in 2006 and 2007. He recommended fans be installed and piping used to remove gas but nothing was done. He became "furious and alarmed" in December 2008 when told there had been 10 gas ignitions and he told the Labour Dept mines inspector the mine should be closed until ventilation was improved.
Bell said the original mine plan stated two tunnels would be drilled through the Hawera fault for ventilation and he was shocked to learn only a single egress would go ahead. He would not have allowed tunnelling through the fault with only one entry to the mine.
The ventilation system was too slow and unable to deal with methane.
A 2009 report found a gas pipeline and other equipment were insufficient to drain methane from the coal seam. It raised concerns about minimal data on gas content, high methane volumes and poor workforce knowledge.
Health and safety manager Neville Rockhouse, whose son Daniel survived the blast, said the company had never planned for an explosion. The mine's safety plans allowed for a fire but simply did not consider that it might explode.
There were initial mechanical problems with the underground ventilation fan which began operating weeks before the explosion and it was not flame proof.
The company had not employed a ventilation officer, despite Pike being a gassy mine.
Did skills or recruitment problems play a part?
Peter Whittall has admitted the experience and competence of staff were a concern. (He wrote in 2005 of the need to recruit overseas and the higher rates of pay available in Australian mines). The company had six different mine managers in two years, three operations managers in 18 months and five technical managers in five years.
A review for the Labour Dept found the company "failed miserably" in its training of contractors.
This week, hydro-mining coordinator George Mason said he had no experience in the hydro coal extraction method and felt out of his depth. The Australian had a 12-year break before rejoining the industry in 2007.
Consultant David Stewart concluded the high turnover of managers had compromised the mine and the mix of inexperienced miners from New Zealand, Australia and South Africa added to the "apparent dysfunctional nature of the organisation and communication".
What other design safety issues have been highlighted?
David Stewart, chairman of the Mines Rescue Service Trust, made 14 audits of the mine early last year as a consultant. He told of problems with the main ventilation fan's equipment and positioning; lack of remote gas monitoring sensors; uncontrolled gas drainage discharge, and a risk of vehicles damaging gas drainage pipes.
Use of a type of concrete instead of steel joists to support the unstable Hawera fault area is alleged to have increased the risk of a rockfall.
A second exit - required by regulations - had been mentioned since 2005 but was never developed. Instead, the company relied on the 108m high ventilation shaft - which included a 55m vertical ladder - for emergency escape.
An audit in 2009 found escape capability an area of serious concern and said escape via the shaft would be "virtually impossible" in a fire.
Miners raised concerns about the shaft with Labour Dept inspector Kevin Poynter in April 2010. Poynter said it could only be climbed with severe difficulty, especially if miners had donned breathing apparatus, and was unsuitable as an escape route. This should have been given the highest priority by the company.
The company believed a fresh air base [a modified shipping container with emergency equipment] was a better option than constructing a secondary exit. The mine tunnel was the primary means of escape.
What else has been heard about the company's safety management and procedures?
The fresh air base had been decommissioned ahead of being moved. When Daniel Rockhouse, one of only two miners to escape the mine, reached the base he found no first-aid kit or breathing apparatus. The emergency phone which was supposed to go directly to the control room instead went to an answering machine. Rockhouse tried another number and got mine general manager Doug White.
Other testimony revealed phones and machinery cutoff switches were not working.
Records list other health and safety failings including the discovery of cigarette butts and a lighter in the mine, faulty gear and methane spikes which were not reported, despite being notifiable.
Two mine deputies were fired for safety breaches leading up to the disaster.
Peter Whittall said he was not aware of any trial evacuation being done using the ventilation shaft.
Dr Kathleen Callaghan, director of the human factors group at the Auckland Medical School, told the inquiry staff kept finding hazards over a significant period of time. "What I don't understand is why they kept repeating."
Whittall said no staff had raised safety concerns with him before the explosion. He said in July the company took "every conceivable step and employed every available consultant" to provide the best possible safety advice.
Why didn't Labour Dept inspectors do anything - eg: act on calls to close the mine until ventilation improved?
Mines inspectors were never shown log books which recorded soaring methane levels and gas sensors that had allegedly been tampered with. Last week, former inspector Kevin Poynter was presented with a long list of incidents but said it was the first time he had seen them. The company never told him of a cluster of methane spikes in October last year, even though they were notifiable events.
Poynter said he made 7 inspections at Pike River over 21/2 years. "I'm there on my own, trying to do the whole lot ...
"[Pike River] are the ones in control of the workplace, not the inspectors," he said to applause from families in the public gallery.
Inspector Michael Firmin was unaware the ventilation fan was not flameproof.
How might the regulatory environment have contributed to the lax safety standards?
New South Wales mines rescue manager Seamus Devlin said he doubted an underground mine like Pike River would be approved in Australia without two designated escapeways.
Former chief mines inspector Robin Hughes traced the origins of the disaster to the 1993 repeal of the Coal Mines Act and a weakened mines inspectorate under the Dept of Labour. Inspections became less frequent and knowledge decreased.
Previously, a large mine like Pike River would have been visited weekly and would have to submit six-monthly plans. The inspectorate group was ditched in 1999 to save $1 million.
Former chief mines inspector Harry Bell said the law changes brought a loss of institutional knowledge.
Last week, the inquiry heard mines inspectors were not trained on underground mining laws.
Mine safety expert Dave Feickert said managers and the men were "really left on their own by the legislative process."
Labour Dept workplace health and safety policy manager James Murphy said New Zealand lacked a code of practice for underground coal mining. The department currently employed only one underground mine inspector (after the second inspector had resigned) compared to seven in 1998.
The remaining inspector, Michael Firmin, said he and former colleague Kevin Poynter had often raised concerns about the number of inspectors and high workload. A third inspector who retired in July 2009 had not been replaced. Ideally, four were needed.
Even the company had called for more mine inspectors - in a 2008 submission to DoL over improving hazard management.
What failings have been found in the emergency response and communications?
Police were criticised for failing to engage with the Mines Rescue Service and local experts who understood underground explosions and ventilation. Mines Rescue believed none of the miners would have survived more than 30 minutes after the first blast. But police maintained hope because two had walked out and the company advised that the mine had additional self rescuers and a fresh air base with an air supply.
The Queensland Mines Rescue team who flew in after the disaster threatened to go home because they were left in the dark over monitoring. They believed the police and Pike River management had no control or management of the mine sealing and recovery aspects.
It took Superintendent Gary Knowles more than eight hours to arrive on site and communications broke down. None of the 17 people working directly underneath him had mining expertise.
Within a day of the explosion, Mines Rescue, the Fire Service and Solid Energy believed a fire was blazing underground but Knowles said he did not realise there was a fire "to that extent."
Peter Whittall told families the men could be sitting around an air pipe waiting to be rescued. Relatives learned about the fire only after the second explosion. At that meeting, Whittall first told them there would be a rescue attempt before police told them of the second explosion.
Whittall said in September he told the meeting that Mines Rescue had been going to enter the mine but people did not pick up on the past tense and started cheering and clapping.
He didn't know until the inquiry that the mine was burning after the first explosion or that film of the first blast existed.
