Another expert, another view on whether the Pike River Mine is safe to re-enter.
The plan is to seal the mine forever, but now an independent report commissioned by the victims' families says it's possible to re-enter the mine to retrieve the bodies.
Another geologist, Dr Murry Cave told Rachel Smalley it can be done.
He said the two kilometre long drift would need to have expensive air-lock doors built every 150 metres and a rock fall on those doors would be the biggest concern.
Dr Cave said anything is possible with the right technology, time, and risk for the people willing to go in.