An Italian mountaineer who climbed the K2 mountain with Irishman Gerard McDonnell has revealed the last moments of the tragic climber's life.

Marco Confortola (37) spoke movingly of how he and McDonnell -- the climber he dubbed "Jesus" -- fought to survive. He also revealed how the Limerickman had spent three hours trying to comfort a number of dying climbers before being killed himself.

It was with McDonnell that the Italian had scaled the peak, reaching the summit at 7pm, just as darkness fell.

The pair embraced, but had little time to enjoy their triumph. They had already seen a Serbian climber plunge to his death and were worried about being stranded.

But after a short descent, they decided it was too dangerous to continue in the dark and stopped for the night.

Confortola dug two small pits with a stick to make a makeshift shelter for the night.

"Since Gerard was having a difficult time, I made his hole bigger to help him lie down for a little bit. Gerard was very cold. I was also cold and began to shiver on purpose to create heat. I was wasting energy, but I needed to get warm."

They were perched on the edge of a sharp slope. "I made sure not to fall asleep, because I could have fallen over," he said.

In the morning, they set out again and after a short while, they came across three climbers from South Korea, hanging upside down, held by a cord attached to their waists. Two were unconscious. For three hours, McDonnell and Confortola tried to right them, but it was in vain. All three died.

It was at that moment, "for some strange reason", that McDonnell began to walk away. It was the last time Confortola would see his friend alive.

Exhausted, he fell asleep, only to be woken by an ominous rumbling. "All of a sudden I saw an avalanche coming down. It was only 20 metres to my right. I saw the body of Gerard sweep past me," he said.

Eleven climbers, including 37-year-old Mr McDonnell from Kilcornan, Co Limerick -- the first Irishman to reach K2's summit -- perished on the Pakistani peak, Everest's slightly smaller but much deadlier brother which has the reputation of being very much harder to climb.

It was the worst K2 tragedy in 20 years.

The mere mention of McDonnell and Confortola's voice turns shaky, his eyes welling up.

"When you are up in the mountains, it's easy to become friends, but it was particular with Gerard," he said. "I used to call him Jesus," he added, gesturing above. "The beard, everything, he looked like Christ. He was always smiling. He was a flower."

The Italian climber shrugged off suggestions that the six teams -- from Ireland, the Netherlands, Serbia, Italy and two from South Korea -- had displayed poor judgment, insufficient preparation and had caught so-called "summit fever".

"We were well prepared," he says. "We had made our plans and even the weather was good."