On 27 March 1977, the deadliest-ever aviation accident occurs at Los Rodeos Airport (now known as Tenerife North Airport) in the Canary Islands. Pan American World Airways Flight 1736 and KLM Flight 4805 collide on the runway in thick fog during the KLM aircraft's attempt to take off, killing 583 people. The poor weather played a part in the disaster, but the fundamental causes of the crash were numerous errors by the pilots of the two aircraft and the airport's air traffic control officers.