"He was well known, well liked. It's like a big family where everyone knows everyone."
Mr Haslett's family are coming to terms with the fact he won't be home for Christmas.
A family statement today thanked everyone involved in the recovery of Mr Haslett's body.
They have asked for privacy "while we work through this tragic event and come to terms with the fact he is not coming home for Christmas."
Mr Haslett was an experienced climber who had been living in Mt Cook village for the last three months.
He was a seasonal mountaineer and employed by the Department of Conservation as part of the Aoraki Alpine Rescue Team.
He and his climbing partner left Plateau Hutt early on Saturday to climb the peak's east ridge.
The alarm was raised about 7.30am when Mr Haslett fell on the north side as they traversed the ridge.
The death has been referred to the coroner and police investigations are ongoing.
But a picture of what happened has now emerged.
"He had to solo climb through a rocky area," Mr Andrew said.
"He has put his ice axe into a rock, and it's levered out, the rock has given way, and he's fallen backwards," he said.
Rescuers say he fell a "long way", about 200 metres, and suffered "extensive injuries".
Mr Andrew said mountaineers were well aware of the risks but added it was "very rare for something like this to happen to someone so experienced".
Mr Haslett worked at Canterbury ski field Mt Cheeseman for six seasons before spending this winter at The Remarkables, near Queenstown.
He started his outdoors career as a "rookie lifty" and ski patroller, according to Mt Cheeseman club president Cam Lill.
He "made his way up" and by last year has achieved his Avalanche Safety Stage 2 qualification - the top qualification for snow safety.
The death of "a passionate outdoorsman" comes as "a big shock" to the tight-knit skiing community, Mr Lill said.
"Stu was a very valued and loyal staff member who made quite an impression on Cheeseman," he said.
"The impact of his death will stretch far beyond Cheeseman. It is the last thing you'd expect from someone you know, especially someone so experienced in the outdoors."
A spokesman for the Aoraki Alpine Rescue team said Mr Haslett was an experienced climber, who was a valued team member, and much-loved member of the community.
"He enjoyed spending time in the Southern Alps and was always professional, courteous and friendly no matter what the circumstances.
"He will be sadly missed and our thoughts are with his family and friends."