Since commercial aviation truly began in the 1930s, the romance of air travel has been marred by the tragedy of crashes. Today, the sky above is safer than ever before but the ground below has become more perilous. That was tragically proven in March, 1977, on the island of Tenerife part of the Canary Island chain where 583 people were killed when two Boeing 747s collided at Los Rodeos Airport. It was the worlds and histories - worst aviation disaster. Though decades have passed, root causes for the tragedy at Tenerife remain with us today.