An underground intercom system at the mine recorded a rumbling sound at 3.44pm, followed by an above-ground operator asking repeatedly if anyone was there, against the background sound of an alarm.
"Anyone underground? Anyone? Anyone?"
Two of the 31 men underground at the time were alive — Daniel Rockhouse and Russell Smith — though they could not answer.
At 4.11pm, electrician Mattheus Strydom, unaware that an explosion had occurred, was sent underground to investigate why electricity and communication had been lost with the mine workings.
He saw what he thought was a body lying on the ground and retreated. It was in fact, Mr Smith who survived the blast and was eventually helped to safety.
At 4.26pm, a manager called Mines Rescue.
Pike River Recovery Agency chief executive Dave Gawn said work on the "recovery’' of the mine drift would continue on November 19.
"As well as normal duties, staff will be involved in supporting the families who visit the site that day. There will be a chance for all staff to observe a silence at 3.44pm."
The underground teams were yesterday at 2133m of 2300m and could see the Rocsil foam sealing plug, which is near the end of the inspection of the drift.
The mine workings where the bodies are believed to be are located beyond that, blocked by a massive and impassable rockfall.
Mr Gawn said it was slow going as the team reinforced the mine ceiling and did forensics.
Once they reached the plug, using long-duration breathing apparatus, they would tunnel through the Rocsil foam plug (about 10m long and big enough for miners to walk through comfortably), then carry out full forensics in the remaining 8m to the rockfall.
After completing their inspection of the drift, the team would return to the area known as "pit bottom in stone" to carry out more forensic work.
The $51 million Pike River Coal mine re-entry is due to finish at the end of this year. It is intended only to search the drift (the stone drive leading towards the mine) for evidence of what caused the explosions, rather than recovery of bodies, which are trapped behind the rockfall.
