Two young Sydney men are lucky to be alive after a slip of the foot sent them both careering 200 metres down a cliff in New Zealand's notorious Mount Cook National Park.
The friends, both in the military, tumbled down a slope in the famous South Island park after one lost his footing during a climb to Kelman Hut, near Mt Annan, on Sunday.
"One of the guys just pivoted on his heel in a momentary lapse of concentration and over he went," Department of Conservation Area Manager Richard McNamara told AAP.
"His mate who was tied to him tried to arrest the fall but got pulled out too and on his way down the would-be rescuer hit a ledge and broke his lower left leg."
That wasn't the end of it, however, with the pair continuing to roll until coming to a stop 200 metres down.
"It was a long, rough fall but thankfully not a vertical one so they were both in ok shape," Mr McNamara said.
Luckily, their fall was spotted by an astute alpine guide who called in the rescue helicopter to recover them and transfer the injured man to Timaru hospital, where he remains in a stable condition.
The men, in their early 20s, have declined media interviews. But park authorities have praised their preparations, saying both were fit, experienced and climbing in clear weather.
"They didn't do anything wrong," Mr McNamara said.
"It was just one of those unfortunate things that sometimes happen despite being prepared with the correct equipment, including safety beacons and flares, and in the right weather conditions.
Mount Cook National Park is one of New Zealand's most popular for climbing, with dozens taking to the slopes daily over summer, but it is also the country's most notorious.
More than 70 people have died in the park since 1907, 34 of them Australians.
Perth doctor Mark Vinar died while descending Mount Cook with brother Miles last December. The 43-year-old fell 500 metres down a near-vertical slope.
Mr McNamara said at the time the experienced pair had been "very, very unlucky".
"Where he fell it's very unforgiving and he fell a very, very long way."