In 1977, on which Spanish island did two Boeing 747 airliners collide on the ground?

On March 27, 1977, two Boeing 747 passenger jets, KLM Flight 4805 and Pan Am Flight 1736, collided on the runway at Los Rodeos Airport (now Tenerife North Airport), on the Spanish island of Tenerife, Canary Islands, killing 583 people in the deadliest accident in aviation history.

A terrorist incident at Gran Canaria Airport had caused many flights to be diverted to Los Rodeos, including the two accident aircraft. The airport quickly became congested with parked aircraft blocking the only taxiway and forcing departing aircraft to taxi on the runway instead.

The collision occurred when KLM 4805 initiated its takeoff run while Pan Am 1736, shrouded in fog, was still on the runway and about to turn off onto the taxiway. The impact and ensuing fire killed everyone on board the KLM jet and most of the occupants of the Pan Am, leaving only 61 survivors from the aircraft's front section.

The subsequent investigation by Spanish authorities concluded that the primary cause of the accident was the KLM captain's decision to take off in the mistaken belief that a takeoff clearance from air traffic control (ATC) had been issued.

Dutch investigators placed a greater emphasis on mutual misunderstanding in radio communications between the KLM crew and ATC but ultimately, KLM admitted their crew was responsible for the accident and the airline agreed to financially compensate the victims' relatives.