Prime Minister John Key has indicated a Commission of Inquiry might be held into the deaths of the 29 miners, while police, the Department of Labour and the coroner will all examine what went wrong.
"There is going to be a range of inquiries that will begin fairly immediately," Energy and Resources Minister Gerry Brownlee said.
"And in the long term of course everyone will want to know what happened up there. It's pretty essential we find out, and the nature of how we achieve that is yet to be determined."
Asked if there were likely to be changes in the mining industry as a result of those inquiries, Mr Brownlee said: "Every time you have something like this you can learn from, of course you make the changes that come from that learning".
Mr Brownlee said he had the same questions as everyone about why and how the tragedy happened.
Grey district Mayor Tony Kokshoorn, in an interview before yesterday's explosion, said he was aware of concerns raised on the West Coast about safety at the Pike River mine.
Mr Brownlee said he had not been told of any series of concerns about that mine by the monitoring agency, the Department of Labour.
"The idea that you invest such a huge amount in an undertaking like this [mine], to somehow put it at risk, is somewhat absurd."
Mr Kokshoorn said: "Over the duration of the construction of this mine, there has been the odd letter to the editor or people raising the fact that it is very gaseous, and it could blow up and this type of thing."
However, he said he understood that the risk in a coal mine related to gas could never be entirely eliminated.
Carol Rose, whose son Stuart Mudge was one of the 29 lost miners, before yesterday's explosion said safety was always paramount at the mine.
"They have got the top safety guy in New Zealand working in that mine, and that guy has got his two sons working in there," Mrs Rose said, in reference to Neville Rockhouse, whose son Ben was trapped in the mine, and son Daniel escaped after Friday's explosion.
"If he's prepared to put his two sons in there working, that's good enough for me. It's just something that went wrong."
The Department of Labour will focus on the Health and Safety in Employment Act; a coronial inquiry is designed to establish the cause and circumstances of death and to make recommendations on how deaths in similar circumstances can be prevented. It can also determine whether the death should be investigated by another authority.
The Commission of Inquiry is a full independent investigation into a matter of major public importance, while the police will examine possible criminal charges arising from the disaster.
