In the early evening of 27 March 1977, two Boeing 747s collided on the runway of Los Rodeos airport (now known as Tenerife Norte), kiling 583. There were 61 survivors. A Royal Dutch Airlines (KLM) plane had started to take off without authorisation, as a Pan-American aircraft was still taxiing in its path.
Neither plane was originally supposed to be at Los Rodeos. Both were heading for Las Palmas in neighbouring Gran Canaria (the Pan-Am from Los Angeles, the KLM from Amsterdam). However numerous planes had to be diverted when a bomb, planted by Canary Island separatists, went off at Las Palmas airport (a small explosion that resulted in minimal injuries). This led to great congestion and pressure at the smaller Los Rodeos airport.
Another factor that contributed to the disaster was the weather - visibility was at less than 400 metres that afternoon due to fog. This caused both pilots to miss key observations.
Once flights were permitted to take off again for Las Palmas, the control tower gave the KLM4805 plane directions to taxi down the runway, then at the end do a 180-degree turn ready for take-off. The PanAm1736 was to follow down the runway a few moments later, but come off at the third exit so the track was clear for the Dutch take-off. Due to the fog however, the PanAm pilot missed the third exit, and continued on to the fourth.
Meanwhile, due to miscommunication with the control tower, the KLM plane prematurely started to hurtle down the runway at top speed to take off, without realising the other plane was blocking its path. The Dutch aircraft scraped the top of the American plane as it flew overhead, tearing off its roof.
The collision caused explosions and fire on both planes. All the passengers on the Dutch plane died as it was engulfed in flames, while 61 escaped the PanAm jumbo, including all the crew in the cockpit.