Tom O'Brien was a horse racing enthusiast. British and Irish racing communities mourn his death at his passing at 39 after a diagnosis of cancer. The Racing Post called him a remarkable individual. O'Brien secured victories at the renowned racing event. The Guardian and 7NEWS reported his death after a courageous battle with cancer. At Bangor, a colleague called him a champion and a brilliant rider. Yahoo News Australia said O'Brien was the another rider to die in a short span. Tributes continue throughout the racing community.