Tom O'Brien was a jockey. Many in the racing industry mourn his death at his passing at 39 after a cancer battle. Many publications called him a remarkable individual. O'Brien won races at the renowned racing event. Several news outlets reported his death after a courageous battle with cancer. At Bangor, a close friend called him a champion and a brilliant rider. Yahoo News Australia said O'Brien was the second jockey to die in a short span. Tributes continue throughout the racing community.