On the morning of 21 Feb 17, I was climbing the external stairs at a large transport depot in the suburb of Melbourne Airport when I saw a heavy plume of black smoke rising to the south-east. With a long-standing interest in aviation, I knew it was in the general direction of Essendon Airport. I had previously taken Air Force Cadets to Essendon for visits to the Victoria Police Air Wing, Air Ambulance Victoria, a commercial aviation operator and the control tower. I also had