The man in charge of the rescue teams at Pike River mine says there was never an opportunity to enter the mine after the first explosion.
Trevor Watts from New Zealand Mines Rescue said the miners were "chomping at the bit" to get underground to help their colleagues.
He told Close Up that talk of a window of opportunity straight after the first explosion occurred was inaccurate, and from the first second after the blast another accumulation of methane was forming.
The explosion ruptured the underground gas drainage line and it immediately began spewing 800 litres per second of methane into the mine, Watts said.
"We had no evidence from our gas analysis that we could put our hand on our heart and say we didn't have a potential ignition source - we knew we had the methane gas there."
The science behind gas analysis is mind boggling and totally different to what it was like 50 years ago, Watts said.
And he said comments that rescuers should just go in there and take a risk were unwarranted.
"If we had sent them in we would have killed between 12 and 18 Mines Rescue members.
"It's not acceptable to go and knock on the door of 12 to 18 Mines Rescue families and say, sorry your men have perished in that mine".
Watts said his staff are highly trained and highly skilled professionals with one of their own colleagues (Peter O'Neill), as well as friends and loved ones, in the mine.
"If we could have got in there we would have done so."
Staff spent the waiting time going through operational planning, risk assessment processes and checking equipment, and Watts said they were in a high state of operational readiness, ready to deploy at a moment's notice.
The men are still united in their desire to go in and get their brothers back , said Watts.
While he would not speculate on timeframes, he acknowledged that with the presumed deaths of all the men underground it provided an opportunity to make the mine more safe for them to enter.
" However long it takes , our men will be there to do their very, very best to recover these guys.
"We will minimise the risk as much as we possibly can, but our men are still going to be faced with hostile conditions."
Watts said the welfare of his staff is absolutely paramount but there is still hard work to be done.
"We've got to prepare ourselves for a tough and difficult task."
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Pike River Miners Relief Fund Trust .
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