Footage of a fire burning at the Pike River mine’s entrance has been shown as the royal inquiry was told this incident was preventable.
Speaking at the commission Australian mining expert from the CFMEU, Timothy Whyte, said the fire on 30 November was avoidable, according to Stuff.co.nz.
The fire was started after contractors attempting to seal the mine used highly flammable polyurethane.
Whyte explained that using polyurethane has previously been ruled out in a risk assessment as it was dangerous.
He went on to say that it seemed as though mine management “simply ignored” the risk assessment.
The fire took more than an hour to be put out and incinerated the mine entrance CCTV.
Sealing of the mine was also delayed by the blaze.
Footage from incident shows the polyurethane sealing foam self combusting before expanding into a large fire.
The burning foam produced hydrogen cyanide, a “deadly gas”, Whyte said.
"If there were survivors [underground], they would have been breathing in hydrogen cyanide."
By the time of the fire, five explosions had already rocked the underground coal mine.