March 13, 1976 - little did he know it but Sir David Murray was speeding towards a crossroads. Driving home having just played in a rugby match on the outskirts of Edinburgh, the then 24-year-old future Rangers owner would be left fighting for his life when a tyre blowout sent his high-powered sports car careering off the road and into a tree. The burgeoning metals tycoon was able to be cut free from the devastated wreckage but the damage inflicted upon his mangled lower limbs gave surgeons no other option but to amputate his legs below the knee. In the days after as he began a gruelling recovery process, Murray realised he had only two directions in which to turn. He could point himself down a path of self-pity and despair. Or he could steer himself along a more productive and determined road, one where he would not allow his life-changing injuries to define him as a person nor a businessman. Now 50 years on, Sir David has opened up on the thoughts and emotions that inspired him to choose courage over resignation . And the four words that he chose to rebuild his life around. While recovering in the hospital, Murray received a letter from hero pilot Douglas Bader who lost both of his legs in an air crash in the 1930s but recovered to fly missions for the RAF during World War two. Recalling the events of that fateful day, he writes in his new autobiography: “On an overcast Saturday afternoon on March 13, I drove my then two-year old son David to Musselburgh after gently persuading him that a nice thing to do would be to buy a bunch of flowers for his mum, Louise. "It wasn’t a special occasion but he was happy to go along. “I dropped him off back at home in Longniddry, East Lothian, then drove the 10 miles to play stand-off for Dalkeith against North Berwick. “I kicked three conversions in a 16-9 victory and then began to make my way home. “ The car – a purple Lotus Elite – had been serviced just 24 hours earlier and unbeknown to me at the time, the tyre pressures had been inflated to almost twice what they should have been. “I also didn’t put my seatbelt on – it wasn’t a legal requirement back then. “As I made my way along a dual carriageway near Longniddry, in East Lothian, the front left tyre suddenly blew. “There was nothing I could have done. “The car lurched to the side, I left the road and smashed headlong into a tree. “Revisiting the scene much, much later, I realised that just a few yards before the tree and a few yards after it, there was nothing but open fields. “How that tree is still standing I don’t know, but remarkably it is. “I recently stopped at the same spot again and nearly 50 years after the accident, there are still marks on the base of the tree. Equally amazingly, there are also still purple shards of the car’s bodywork embedded in my upper leg. “Memories of the exact moment are hazy. The vehicle was made of fibreglass and the impact forced the engine block right through the facia and into the driver and passenger seat. “I was immediately shunted right through the door and lay unconscious and bleeding next to the wreckage. If I’d been wearing a seatbelt, I’d have been stuck in the car – things might have been much worse. “A number of rugby supporters who had actually been at the game stopped their cars and raced to my side. There was lots of blood and they applied tourniquets with their ties to try to halt the flow. “They somehow kept me alive and even though I can remember nothing about it, an ambulance was called and arrived quickly to take me 18 miles to Edinburgh Royal Infirmary. “That night, I lost 13 pints of blood and there was no option for surgeons but to immediately amputate parts of my mangled legs through the knees.” Murray made his fortunes in the metal game. At its peak, his company was turning over £350million and selling 450,000 tonnes of steel a year - equivalent to the materials needed to construct a dozen Forth Rail Bridges. But it was his own iron-clad resolve that proved to be his most valuable personal commodity as he battled back from his brush with fate. He adds: “ My wife Louise, of course, was frantic with worry yet somehow I’d managed to call her from a hospital payphone while lying on a trolley taking me back to the ward. “I told her, ‘You have to come. I’m in a bad way.’ I have absolutely no recollection of this. "Louise, my family and friends took turns to sit by my bedside during the following days as I struggled to recover. “The anaesthetist Ned Trench and a surgeon fought to give me a better chance of a partial recovery, but five days after the accident they were finally defeated after an infection set in. “I ended up having a further nine inches of my legs removed. Following this I was finally transferred to the Princess Margaret Rose Hospital for 10 weeks of intensive care. “I must have spent days and hours wondering how I might cope with the rest of my life. I was still a young man, with a wife and young family and I was passionate about business and playing sports. I just felt numb but then that letter arrived and it made me so determined to carry on. ‘I admire your courage’… four words that have long had a bearing on so many aspects of my life. It became a blueprint. Four words that a doctor or a nurse at my bedside in the hospital might have been expected to utter and if they had, they might have been referring to the fact that I apparently had never cried. Not once. "The reason I have built so much of my life around those words is that they were conveyed to me – in a private letter – by a man who personified courage: Sir Douglas Bader. "Like millions of others I was only aware of him because of the 1956 British war film Reach For The Sky where Bader was played by Kenneth More. In 1976, at the age of 24, I had just lost both of my legs – in a car crash – and was lying in hospital, a bi-lateral amputee, when the nurse delivered the letter that would act as a motivation throughout the rest of my life.” Former Ibrox gaffer Graeme Souness describes Murray in the book as “the most competitive human being I’ve ever met”. It was that defiant streak the millionaire, now 73, leant on as he was forced to to learn to walk again with the aid of prosthetic limbs. And that determination was key to his establishing a billion-pound business empire and footballing dynasty that would see Rangers dominate Scottish football in the 1990s. “In life, I never try to look back,” he adds. “We all have decisions to make – some of them big, reflective moments – and I am a great believer in the fact that you either turn left or you turn right. “If anyone I know is ever in trouble or facing adversity, I always tell them that every problem has a solution and to always look ahead. “Be decisive. Stay positive. I had no intention of quitting.” Mettle: Tragedy, Courage & Titles by Sir David Murray, published by Reach Sport rrp £22, is on sale Thursday 3rd July from Amazon and all good bookshops Preorder on Amazon HERE