When Jason Kennison's mum spoke to her son on Thursday, as he scaled the slopes of Mount Everest, she had no idea that "I'll always love you" would be the last words she would ever say to him.
After reaching the summit, the 40-year-old mountaineer "suddenly fell ill" during the descent on Friday morning, without getting the chance to have another conversation with his family.
"The last ... FaceTime we had was on Wednesday and he spoke to … me in the garden and he showed us his tent, and he showed us his washing drying in his tent … and the view from his tent," his mother Gill Kennison said.
"Then he rang me Thursday.
"He said, 'Mum we're doing the big walk to the summit at night', and I couldn't hear what he was saying, and he said, 'I'll see you when I get back'.
"And I said, 'Well just remember Jason please take it easy, take care and remember I'll always, I'll always love you', and that was the last words we said.
"Knowing they were my last words to him was comforting, I guess, in a way."
Mr Kennison was originally from South Australia, but had since moved to Perth.
His family, including his mother and brother Adrian, paid a deeply heartfelt tribute to an "absolutely amazing" person who exemplified "determination" and strength of spirit.
"An amazing son, amazing brother, amazing uncle, he was just on top the world — literally on top of the world," Gill Kennison said.
"Whatever he wanted to achieve, whatever he wanted to do, he put in 110 per cent — he just went out and did it, and tried to do it and tried to achieve it, and nine times out of 10 he did.
"He was just so determined, so full of life."
Speaking from the family's hometown of Mallala, north of Adelaide, Gill Kennison was surrounded by family members including Jason's brother Adrian, who spoke warmly of his sibling's achievements.
"Whether it was playing football as a kid, winning motocross races, or working around the world in the mining industry and in high-risk environments, he did all the training he could in preparation to achieving his new goal of climbing to the top of Mount Everest," he said.
"He made it in high spirits doing what he wanted. There was the climb up, he had his photo on top of the summit.
"On the descent he suddenly fell ill and that's when he passed away."
Mr Kennison, who twice had to learn how to walk again, trained for the climb to raise funds for Spinal Cord Injuries Australia.
"We were beyond shocked to hear the news of his passing whilst undertaking such an incredibly inspiring feat," the group said in a statement.
"He was a shining example of overcoming the odds and Jason showcased incredible tenacity and determination in everything he set his mind to."
At the age of 23, he was in a vehicle accident which resulted in traumatic injuries, leaving him with the fear that he "might not walk again".
"He had his own battles, everyone's got their own battles, but he set every goal, one step at a time," Adrian Kennison said.
"Our parents are very strong, independent people and he's got, as you can see, massive family support.
"We're a large family — we support everything that everybody does."
Gill Kennison said her son's strength of spirit was among his strongest attributes.
"He had his struggles mentally and physically, but he always had that strength, determination, stubbornness which he gets from his father — not to give up," she said.
"It was a struggle for him then mentally to come out of that dark place, but with help and support he did, and again, it's Jason words, 'one step at a time'."
The family said a memorial service would likely be held in Mallala.
