Pike River Coal chief executive Peter Whittall has told the Pike River inquiry he thought it was a drill when told about the explosion.
Formerly the mine manager on the West Coast until his promotion, Mr Whittall was in his Wellington office when he was called on November 19, an hour after the blast.
He asked if it was a drill because he knew staff were ready to do one, he told the royal commission of inquiry in Greymouth.
"I've never had a phone call to tell me there's been an explosion before. Initially I was quite numb."
Mr Whittall also said that the day a 55m-high vertical escape ladder was tested, he was dressed to go underground and staff were waiting for him in the mine, but he was redirected to corporate matters and spent the day in his office in overalls. Only two of the four men made it part of the way up because it was such a demanding climb, he said.