Two Boeing 747, Pan Am and KLM collide on the runway of Tenerife by 575 deaths, the heaviest stock in the history of aviation.
Both aircraft had been diverted from Las Palmas airport, closed for a terrorist attack to that of Los Rodeos Tenerife with its single track.
The KLM B747 had 250 people on board the B 747 near the PanAm 400. Only sixty survivors, all of Panama will be counted.
A misunderstanding of the radio messages will bring Panama to cross the track late on the wrong ramp, while the KLM thought he had permission to take off, clear track.
Other causes of the crash were as thick fog making visibility very poor and the exceptionally high traffic density at this airport has increased the stress on controllers and pilots.