On thAT day just over five years ago when I got a call to say my friend Ger McDonnell was in serious trouble on K2, the world's second highest and deadliest mountain, little did I realise that the fallout from his tragic death would lead me on a five-year search for the truth.
This journey would take me round the world and end with the production of a feature-length documentary with my film partners and a book with my co-author Pemba Gyalje Sherpa.
Ger, from Kilcornan, Co Limerick, was among a group of 18 climbers who, on August 1, 2008, had reached the summit of K2 – the mountaineer's mountain, the Holy Grail.
But, sadly, Ger was among a total of 11 climbers who never came home following the worst single accident in the history of K2 mountaineering. And I wanted to know why.
Ger was special. He had an ability, in the words of his partner Annie Starkey, to light up a room when he entered it.
He was warm, loving and full of life. Mountains were his playground, his escape, his passion.
In Ger I found a kindred spirit who shared that irresistible urge to visit and explore the most beautiful, but often most dangerous, parts of the planet.
He was a deeply conscientious climber, always willing to push himself to the limit, but always committed to safety and ever willing to come to another climber's aid.
Ger and Pemba Gyalje Sherpa – a climbing partner and friend of mine from Nepal – were part of the same 2008 expedition to K2.
On August 1 as the summiteers made frantic efforts to descend the mountain in the dark – many of them becoming trapped above 8,000m in the Death Zone – Ger acted with a compassion and kindness so rare in modern-day mountaineering.
When he and an Italian climber came to the aid of three members of a South Korean expedition trapped and hanging on ropes on an almost vertical ice-face, Ger spent several hours trying to free them.
What happened next became the subject of a long-running controversy in which different stories emerged.
The many conflicting accounts of what had happened to Ger and others compounded the trauma and distress of the families left behind.
Pemba Gyalje had been at the centre of events on K2 but few in the media had bothered to wait for his account in the rush to judgment and the haste to publish the most lurid and dramatic headlines.
When I spoke with Pemba about the tragic events, I knew that there was more to this story than met the eye.
Within months, I had partnered with producer and director Nick Ryan and his team at Image Now Films in Dublin.
We began interviewing Pemba and other Sherpas, who were heroes on the mountain on those dreadful days.
The survivors worldwide gave generously of their time and memories, providing the most complete interpretation to date of one of modern-day mountaineering's worst tragedies.
The documentary film 'The Summit' – which has already won a host of international awards – is released in Irish cinemas tomorrow.
An accompanying book, 'The Summit: How Triumph Turned to Tragedy on K2's Deadliest Days', which I co-authored with Pemba, was also launched this week.
It has been an emotional journey but throughout it all, I have tried to remember the good times with Ger, his ever-smiling face, his positivity and warmth.
I hope that my long search for the truth with director Nick Ryan and the teams involved in the film and the book, can help bring a clearer picture of what happened – for Ger's loved ones and the ten other families left behind.
Pat Falvey is an Irish adventurer