State-owned coal miner Solid Energy's plans to turn low-grade Southland lignite coal deposits into massive new industries make no sense and the coal should remain in the ground, says the Parliamentary Commissioner for the Environment.

The fire which has been raging for days at the Pike River Coal mine is definitely out, say Australians brought in to operate the GAG jet unit which has been pumping carbon dioxide into the mine.

Pike River Coal will have to reduce its workforce when it is ready to re-establish operations, but CEO Peter Whittall says reports of possible receivership were "extremely premature".

Rio Tinto Group, the world's third-largest mining company, has made a A$3.5 billion ($4.53 billion) takeover proposal for Riversdale Mining, which is developing coal mines in Africa.

Pike River has rejected claims management was not approachable for staff with safety concerns before the November 19 blast.

Firefighters were last night battling to cool the extremely hot concrete pad around the Pike River mine vent shaft.

An operation has begun to extinguish the fire coming from the vent shaft of the Pike River mine and cool the surrounding concrete pad, using water pumped up from a nearby creek.

Balloons replaced candles as the birthday of one of the Pike River Mine 29 was celebrated yesterday in the first individual memorial service.

It could take weeks for a GAG unit to put out a coal fire in the Pike River mine, police say.

Tables representing the 29 Pike River workers were a focal point for 11,000 mourners yesterday.

The strength of the West Coast community will help it overcome its collective grief over the deaths of the 29 men who died in the Pike River mine tragedy, Governor-General Sir Anand Satyanand said today at the memorial service in Greymouth.

John Key today delivered a personal message to the mothers whose children have been left fatherless as a result of the Pike River mine tragedy. His was one of several moving tributes at today's Remembrance Service.

"Our lives changed forever" when the Pike River Mine exploded, the mining company chief executive told mourners today.

Several thousand people have filled Greymouth’s Omoto Racecourse and numerous MPs and city mayors have taken their seats on the main stage for the Pike River Official Remembrance service