Timeline - Pike River mine explosion
12:10pm: Buses carrying families leave the mine site
10.18am: A large truck carrying drilling equipment arrived at cordon outside mine.
10.12am: Families of missing men arrive at mine site.
10.02am: Energy Minister Gerry Brownlee said he was drawing hope from the Chilean rescue
10am: Greymouth mayor Tony Kokshoorn says he wants names of the missing released.
9.30am: Families of missing men leave Greymouth on buses for the mine site.
8.31am: Pike River chief executive Peter Whittall says ''we just don't know what ventiliation devices are still standing up.''
8.30am: Police Superintendent Gary Knowles, the Tasman Police District Commander and the man in charge of the rescue, says "I am not going to put 16 guys underground and risk losing them to effect a half-arsed rescue."
8.28am: Police Superintendent Gary Knowles, the Tasman Police District Commander and the man in charge of the rescue, says families understand safety remains paramount.
8.22am: Pike River chief executive Peter Whittall says rig will drill down into the mine to take samples.
8.20am: Pike River chief executive Peter Whittall says Pike River will be running representatives from families up to the mine in buses this morning.
8.19am: Pike River chief executive Peter Whittall said there is heating of ''some sort ''under ground - some combustion of material which is generationg poisonous gases.
8.15am: More than 150 media from around the world at latest press update.
8.10am: Police Superintendent Gary Knowles, the Tasman Police District Commander and the man in charge of the rescue, leaves meeting with families and says they are still focused on getting the men out.
7.26am Sunday: All Blacks and Black Caps send message of support. Richie McCaw says their "hearts" go out to families and friends of miners.
7.35pm: Police confirm there will be no rescue attempt on Saturday.
6pm: Police Superintendent Gary Knowles, the Tasman Police District Commander and the man in charge of the rescue, says police will resume air testing in the morning.
5.30pm: Pike River Coal chairman John Dow repeats police comments on the prospect of a rescue that night, saying it was unlikely.
4pm: Police withdraw teams checking air samples at the mine because of a drop in air quality.
3pm: The next media briefing is not expected to take place until 8am tomorrow. Stuff.co.nz will continue to update this story throughout the night.
2.25pm: Prime Minister John Key says "hearts and thoughts" go out to families. He says support has been offered from overseas, including an email from Prince William.
2.10pm: Superintendent Gary Knowles, the Tasman Police District Commander who is leading the rescue effort, says: "We're ready to go, as soon as the environment changes... could happen overnight, it could happen in the next hour.
"I'm an eternal optiomist. I still think we're going to go down and find these guys."
"It is a very fine balance, not going to put 16 men underground and risk their lives. Safety is paramount."
2.06pm: Pike River chief executive Peter Whittall says families are more than welcome to talk to "anyone they wish to" and that there's no media ban.
2pm: Press conference gets underway. Whittall says air quality tests from this morning were inconclusive with no trends visible yet as not enough samples had been done to be conclusive. Levels of methane, ethane and carbon monoxide are being tested.
1.12pm: Police say they are still awaiting tests before entering the mine, despite the mayor saying the OK has been given. Search and rescue teams have not begun their rescue yet.
12.04pm: Search and rescue staff set to enter West Coast mine after tests come back clear.
11am: Grey District Mayor says one of those trapped underground is Blair Sims, a regular player in the centre or on the wing for the region's rugby league team. Sims received the West Coast Player of the Year Award the last two years running, as well as being picked for the newly established South Island team this year.
10.42am: A female relative of one of the trapped miners, who lives in Rutherglen, near Greymouth, says it is "hard to do anything at the moment''. "All we can do is hope and pray,'' said the woman, who asked not to be named.
10.11am: Greymouth churches will hold special services tonight to comfort families and to pray for a successful outcome at the mine.
9.41am: Police say specialist gas testing equipment has been flown in from Australia this morning to help with the rescue operation where 29 men remain trapped underground.
8.40am: Next press conference and update is scheduled for 2pm.
8.34am: Pike River Coal chief executive Peter Whittall says the youngest man underground is 17 while the oldest is 62-years-old. A mix of New Zealanders, Australians and British nationals make up the 29 men.
8.31am: Whittall says he has no knowledge about the men underground being alive and he doesn't want to speculate as to whether they are still alive. He says families are stressed and it is difficult to find all next of kin because many men are single and not from the West Coast.
Families were briefed at 7am this morning and have been hugging each other and holding hands.
"The mining industry is close-knit. Watching and waiting and hoping for their loved ones to return."
8.25am: Whittall says the men underground will be within several hundreds metres of each other. There's no predicting how they will be behaving underground. He hopes they are sitting at the end of the fresh air vent, sitting tight and waiting for rescue. The company is monitoring air ventilation to the mine, trying to get accurate gas samples. They can't risk sending men in, for fear to both rescuers and also as it may jeopardise the men underground by causing a second explosion.
8.21am: Whittall assures family they are doing all they can to bring the men out. He has no idea what has caused the methane explosion, and refuses to speculate on the reason.
8.20am: Whittall says one miner who walked out was knocked to the ground by the explosion and knocked unconscious. Both miners who walked out are shaken with minor injuries, he says and have suffered shock.
8.17am: Peter Whittall says there are 29 people below ground. There were no prior concerns about methane gas. He says one advantage is a tunnel mine, instead of a mine shaft. Inspector Gary Knowles, Tasman police area commander vows to “bring the boys home.”
8.02am: Huge media contingent gathers for a press conference. Gerry Brownlee and Kate Wilkinson arrive.
Saturday 6.48am: Police announce a press conference for 8am with Superintendent Gary Knowles, the Tasman Police District Commander, and Peter Whittall, Pike River Coal chief executive. Rescuers are still at the mine site but have so far been unable to get underground or make contact with the miners and contractors trapped inside.
Update from overnight: Still no communication with any of the 29 trapped miners underground.
10.54pm: Labour Leader Phil Goff says he is praying for the trapped miners. "Our thoughts and prayers are with the miners, their families who are waiting anxiously for news and for the West Coast community which is shocked by the incident and its potential consequences."
10.24pm: One of the missing miners was last night named as Greymouth District councillor Milton Osborne. Greymouth mayor Tony Kokshoorn said Osborne was a contractor at the Pike River mine, and was among the 27 men unaccounted for after the explosion.
10.17pm: Police request Civil Defence and New Zealand Red Cross set up a Welfare centre in Greymouth to cater for families of the miners trapped.
9.29pm: Greymouth mayor Tony Kokshoorn, who also attended the conference, says it could take days before it is safe enough for the specialist rescue teams to re-enter the mine.
"We are holding on to hope. Look at Chile, all those miners were trapped and they all came out alive.''
9.12pm: Pike River spokesman Dick Knapp, speaking at a cordon site about 12kms from the mine entrance, says 27 miners and contractors remain underground - 15 employees and 12 contractors. Families are being asked to gather at Moonlight Hall near Blackball to wait for news, and they will also receive support and information there.
8.24pm: St John confirms it has set up for a "long operation”.
8.02pm: Energy Minister Gerry Brownlee says the Government will offer whatever assistance is needed.
8.01pm: A New Zealand Flying Doctor plane with five people on board - including medical staff and management - is about to take off from Christchurch Airport.
Police spokeswoman Barbara Dunn says police officers have gone to Greymouth Hospital to interview the two miners who have emerged.
St John has taken two patients to the hospital, both with minor injuries.
Dunn has no further information on the men's conditions but says: "They did walk out so that's a good sign''.
7.58pm: A crisis unit is being set up at a Greymouth Red Cross base. Trucks carrying air vents have just crossed the cordon at the entrance to the mine and two utility vehicles carrying stretchers have also driven in.
7.53pm: Robin Kingston, archdeacon of the Greymouth and Kumara Anglican Church, said many of the church's parishioners were involved directly or indirectly with the Pike River Mine. "There is a significant amount of nervousness around at the moment. People have been asking for prayers for those they know who are not accounted for as yet."
7.40pm: Engineering, Printing and Manufacturing Union national secretary Andrew Little said it was an ``incredibly anxious'' time for the miners' families.
``We've got a [union] organiser over there who is with families. The only thing we can do is provide support, which is what we are doing at this point,'' he said.
7.34pm: Energy minister Gerry Brownlee confirms he is heading to Greymouth tonight.
7.29pm: Police update says the two miners who escaped indicated three of their colleagues were also on their way to the surface. The mine entrance is about 2.2km long and then branches out into sub areas.
Concerns raised that ventilation inside the mine shaft may be compromised by the power outage.
7.19pm: Pike River chief executive Peter Whittall said he had not received any reports that someone was dead
"My understanding there is no evidence of fatalities at this stage," he told Close Up.
7.14pm: Pike River chief Peter Whittall says communication with the afternoon shift was lost at 4.10pm and he does not know of any fatalities.
He says 27 miners were on the shift and two have walked out and were being treated.
Police begin stopping vehicles at the private road leading into the mine, saying the road needs to remain clear for ambulances.
Some of the missing miners' family gather at the mine entrance further up the private road waiting for news of their loved ones. Two rescue helicopters land at the scene.
St John confirms two male patients have been taken to Grey Base Hospital with moderate injuries.
6.58pm: Reports of a body being removed from mine. This is later discounted by Pike River management.
6.54pm: Police say early indications are that there was a power outage at the mine late this afternoon. Police say an electrician went into the mine about 3.50pm to investigate the outage and discovered a loader driver who had been blown off his machine about 1500 metres into the mine shaft.
6.29pm: West Coast area commander Inspector John Canning reports miners could be 1,500 metres underground. Police were notified an hour after the men failed to report - as was the practice in such emergencies. He says the mine rescue team has been called in, with members coming in from around the West Coast.
6.11pm: St John activates its national emergency response plans and say six ambulances are at the scene and three rescue helicopters are on the way from Nelson, Greymouth and Christchurch.
5.51pm: First reports that two miners have surfaced; 33 still unaccounted for.
5.29pm: Chairman John Dow refuses to comment when contacted by The Press, but says he has spoken to chief executive Peter Whittall who will comment soon.
5.23pm: Police issue first statement to media saying they were at the Pike River Coal Processing Plant in Atarau, about halfway between Greymouth and Reefton. Police confirm there had been reports of an explosion.
5.09pm First unconfirmed reports of around 25 people trapped in the mine.
4.53pm: Emergency services begin to respond to the situation at Pike River.
Friday 3.45pm: First reports of explosion at Pike River mine, 50km north-east of Greymouth.