Video | New Zealand braces for mine deaths

Nothing has been heard from the trapped miners since the explosion tore through the Pike River colliery. Rescurers are unable to go underground due to several dangerous gases in the mine.

Even though emergency crews are racing to finish drilling a small hole through to the mine shaft, rescue operation chief said they had to prepare for fatalities.

“We still remain optimistic, we’re still keeping an open mine but we are planning for all outcomes and this also includes the possible loss of life as a result of what’s occurred,” a police superintendent said.

One of the only two men to make it out of the mine described a huge explosion and being surrounded by thick white smoke.

“I got up and there was thick white smoke everywhere, worse than a fire. I knew straight away that it was carbon monoxide,” he said.

Rescuers are drilling a 15-centimetre (six-inch) hole through to the mine shaft, which would be used to take air samples and funnel laser-imaging equipment and video cameras down.

The plan also includes sending a remote-controlled robot carrying a camera part way down the mine shaft, although it can only operate where where there is fresh air not in a gaseous environment, as rescuers previously thought.

The bore hole should be completed Monday night, Pike River chief executive said.