Pike River - a fatally flawed design mandated by Gubmint

Pike River was at base a Gubmint-enforced faulty design, and any regulatory 'failure' was well downstream of that.

1. The seam at PRCC sloped upwards, through known-to-be-gassy coal (it's substantially the same as coal found at Brunner and Strongman - both famous historic disasters).
2. This should have placed a very high design emphasis on excellent mine ventilation.
3. DoC controls both the surface over the seam (Conservation land) and the outcropping face of the seam (the escarpment is in Paparoa National Park).
4. A sensible ventilation plan would have been to allow either or both of vertical vents up to surface through overburden, and vents right along the top of the seam straight out to the escarpment. Both would be natural ventilation (methane is lighter than air, and both sets of vents would vent up). As mine roads were driven, they could have been vented up and out, with less mechanical assistance needed and much greater margins of safety.
5. DoC would allow only one vent hole in its precious Conservation Estate, and would not even consider a vent on the escarpment above the seam.
6. The one vent allowed was at the lowest point of the coal seam (the least likely place to accumulate and vent methane without yuge mechanical assistance).
7. This was an inherently flawed design (the Royal Commission could find only one other similar design across the globe, and IIRC That went Boom, too)
8. It was, in short, an accident waiting to happen, from a design forced by Gubmint intransigence to be fatally deficient.
9. To be sure, mine management failures were also there. But managing a lemon tends to produce a bitter result regardless.