After the gales, thunderclaps and fatal lightning strike on a rider and horse that afternoon, it is easy to be wise in hindsight. At least the parents, friends and principal of the school pupils who died in the Mangatepopo River have resisted the urge to blame.
Their response to the tragedy has been a credit to them. The evident faith the school upholds allows them to accept the fate of their teacher and classmates without the questions others might raise, but faith does not shield anyone from anguish.
They have shared theirs openly and with a dignity that does not always accompany public grief these days.
Principal Murray Burton said, "I will not deny that I am angry ... It's not an anger that is white hot - it's, 'Why us? Why this? Isn't it needless?'"
How can they be answered? We reported on Wednesday that the downpour had been half the size of that in Cyclone Bola, which hit the North Island's East Coast in the autumn of 1988. The soil of the Central Plateau, parched after a summer like this, could have been expected to absorb a dumping. We have sought to explain the flash flood phenomenon in the paper today.
It would need no explanation to the outdoor pursuits centre. Its business is to know the behaviour of the land, rivers and streams around it in all weather. It takes young people canyoning to experience precisely the action of water, rock and forces of nature in such places.
The head of the centre, Dr Grant Davidson, said that within 30 minutes of 3pm the tiny river had risen from its usual 0.5 cubic metres a second to deliver as much as 18 cubic metres a second, equivalent to the flow of the nearby Tongariro River. By 4pm the Mangatepopo was back to normal. The "rain bomb" had dropped, he said, after the worst drought of his 24 years at the centre.
Two survivors of the school party say that no blame can be placed on the centre's instructor in the river with them.
She tried to guide the group to safety using a rope and might not have been aware that around the bend the river had topped a dam. Her decision saved four, but many others could not reach her as she waited to grab them. The swirling water carried them over the dam to rocks below.
The various inquiries under way will examine events more closely, but hopefully there is no need for blame. A father of one of the victims has attributed the tragedy to "one of those freak moments - one of those once-in-a-million-year things".
Adventure with nature is often described as a challenge, never without risk. On the occasions that nature issues a reminder of that fact, it can be a conceit to find human fault. A little awe is in order, of the event and the bereaved who are blessed with acceptance.
