Mountaineers on Mt Cook have told rescuers of the moment a rock slide came surging towards them and described it as both terrifying and "pretty amazing".
A group of 15 people had to be evacuated by helicopter last night after the huge rock slide off the West Face of Mt Dixon, which fell about 900 metres shortly after 2pm.
It missed the popular alpine hut - Plateau Hut - where the group was situated, by around 150m.
Dramatic pictures show a huge mound of rock and smoke billowing from the mountain. The hut - just a speck - can just be made out.
Department of Conservation worker Shirley Slatter, who is based at Mt Cook, said it was a miracle no one was injured and it was very lucky the rock fall had not reached the hut.
After visiting the group yesterday afternoon, she said many of them described the moment as scary, while others said it was an amazing thing to see up close.
"They're certainly a little bit shaken. It was coming down at a fair rate ... and it was coming across the plateau towards the hut."
Chris Braugh, from the Helicopter Line, spotted the debris during a sightseeing trip and said it was the biggest he had seen.
"It would have been a pretty big roar."By Edward Gay @edwardgay Email Edward, Vaimoana Tapaleao Email Vaimoana