News that all 28 miners trapped by a fire inside a Waihi Gold underground mine today have been successfully rescued is a "huge relief" for their families, says Hauraki District Mayor John Tregidga.
He said he was "absolutely delighted" that the miners have been evacuated safely but there are still questions about what caused the emergency.
An investigation has been launched into the fire inside the mine after rescuers successfully evacuated all 28 trapped miners.
A truck engine caught fire in Newmont Waihi Gold's Trio underground mine at about 5am, leaving the men trapped in three refuge chambers.
Mines rescue staff had evacuated thirteen of the miners by 10.30am, while 15 remained trapped in a rescue chamber deep in the mine.
Waihi Gold general operations manager Glen Grindlay said the remaining men were rescued by 12pm after seven hours in the chamber.
One man would seek medical attention for smoke inhalation, he said. There were no other injuries.
"All are in good spirits, they're very happy actually, Mr Grindlay said.
"I believe some of them thought it was a drill."
Mr Grindlay said the fire in the mine was now "contained to a stock pile".
The 35 tonne Komatsu truck had burnt out while rescue teams sought to get to the trapped men, he said.
"We opted to go for the personnel first and worry about fire later".
The cause of the fire was unknown, Mr Grindlay said.
"This will obviously be the focus of our investigation at a later stage."
Mine spokesman Kit Wilson said the miners had followed procedure by heading to rescue chambers when the fire broke out.
"In coal mines you get out. In gold mines you wait it out."
Mayor Tregidg said the rescue team was "world-class".
"It's great to see that with the training they've had that they've been able to get them all out so quickly.
"I'm still very interested in how this has happened and I'll be waiting for that report.''
Mr Tregidga said the mining company recently lodged an application to extend its operations at Waihi.
Its practices would be put under the microscope after this morning's incident.
"I still have concern about how did this happen. In a world-class mine and with a further underground [mining] application, I'm very keen to find out what caused this and how did it happen.
"The early indication is that it's a diesel engine that caught on fire. You would think vehicles being used underground are well serviced.
"I want to understand what caused this ... [and] was it a maintenance issue? I think the public and the workers are wanting to know."
Family members are gathering at the mine as their loved ones are slowly evacuated.
Counsellors are on site to speak with the men and their families. Some of the men have already left in vehicles either to meet with family at another gathering point in the township or to go home.
DEBRIEF TO FOCUS ON PROCEDURE - UNION
Engineering, Printing and Manufacturing Union assistant national secretary Ged O'Connell said the final 15 miners reached the surface shortly before midday.
"We're very, very relieved everyone's out unscathed," Mr O'Connell said.
"They're now entering into a debrief situation over the next hour or so and they've invited us [the union] into it to just consider how the evacuation process went."
Mr O'Connell said the debrief would help evaluate how the miners reacted to the truck fire and how effective the evacuation procedures were.
"We're not rushing into finding out the cause [of the fire] at this stage. The key thing for us is to ensure the evacuation procedures went well and it appears they did,'' Mr O'Connell said.
He said part of the debrief would be speaking with the miners about how they are coping.
"Part of that ... is what are their needs, whether they need to take time out, how they are coping."
Mr O'Connell said a lot could be learned from the evacuation.
"Particularly the fact that there has been no casualties ... it is a chance to get stuck in now and do a detailed debrief and learn as much as we can about the situation. Were there good procedures in place? Were people aware of them? Did they go with [the procedures]? How effective were they?"
MINE WELL-EQUIPPED - LOCAL COUNCILLOR
Waihi ward councillor Sel Baker said the refuge chambers in the mine were equipped to keep miners alive for up to 36 hours.
They were completely sealed and equipped with oxygen, water, communication and even packs of cards, he said.
"There could be a fire a couple of feet away and they'd still be okay.
Mr Baker said black smoke billowing out of the mine had reduced significantly by 11am.
He said the truck that caught fire would have had a payload of about 60 or 80 tonnes and wheel at least seven feet tall.
"These things can burn for quite a while."
All operations at the mine were stopped.
Security guards were in place at entrances to the mine and a public access way was blocked off.
Public tours of the gold mine were cancelled for the day.
MAYOR CONSIDERS RETURN
Hauraki District Mayor John Tregidga, who is at a local government conference in Wellington today, said he was considering returning to the region as soon as possible depending on the evacuation of the remaining trapped miners.
Mr Tregidga, who is being updated by his staff and officials from the mine, said he was not aware of any previous similar incidences at the mine.
"But they've got an amazing rescue team, hugely experienced and trained," he said.
ABOUT THE MINE
Newmont Waihi Gold is owned by Newmont Mining Corporation which is based in Denver, Colorado. It operates on five continents.
The company manages the Martha, Favona and Trio mines in Waihi.
The trio mine, situated under Union Hill, is due for completion in 2014.
It's about halfway between the Martha open pit mine and the Favona underground mine in Waihi.
Construction on its twin drives, which are 590 metres and 790 metres long, began in 2010.
About 350 people are employed at the Waihi Gold mines.
Any members of the public inquiring about the fire should call 0800 639 6668.
* Read Grant Bradley's March feature on development at the Newmont Waihi Gold Mine here.