THE DISASTER IN TENERIFE

Neither Boeing 747 jumbo jet — Pan Am Flight 1736 nor KLM Flight 4805 — was supposed to be on Tenerife that day. Both planes were carrying passengers to another of the Canary Islands, Gran Canaria. The Pan Am flight was a charter carrying mostly Americans to join a cruise. The KLM flight from Amsterdam was full of tourists.

That afternoon, however, terrorists set off a bomb at Gran Canaria Airport. While officials unsuccessfully searched for a possible second explosive, all incoming flights were diverted to Los Rodeos, a tiny airport at Tenerife that had only one runway.

The captain of the Pan Am flight kept his passengers aboard during the layover. The captain of the KLM flight elected to pull up to the terminal and let his passengers disembark during the wait. He also decided to refuel his plane.

When it came time to resume the journey to Gran Canaria, the two jumbo jets had difficulty maneuvering around each other and difficulty understanding instructions from the ground controller in the airport tower. Because of a series of misunderstandings, both 747s ended up at opposite ends of the runway, facing each other — but with decreasing visibility, due to fog. Neither pilot could see the other plane. Nor could controllers in the tower see either plane.

The pilot of KLM Flight 4805, growing concerned about how the delay might affect strict Dutch overtime rules, began the roll for his takeoff before he was given permission from the tower. Meanwhile, Pan Am Flight 1736 was on the runway, taxiing to a spot to where it had been directed.

The pilots of the planes saw each other moments before impact. The Pan Am pilot attempted to veer off into the grass while the KLM pilot shoved his thrust levers forward and tried to pull his plane into the air. Traveling about 160 mph, the left side engines, lower fuselage and main landing gear of the KLM plane struck the fuselage of the Pan Am plane, ripping it apart. The KLM plane hit the runway, skidded a thousand feet and burst into flames that would take firefighters hours to put out. All aboard — 234 passengers and 14 crew — were killed.

Passengers sitting near the front of the Pan Am plane managed to escape through holes in the fuselage and then walking out onto the intact left wing. Of the 396 aboard the Pan Am plane, 61 survived, including the three-person cockpit crew.

As a result of the accident, changes would be made to international airline procedures, standardizing language used while directing traffic in the air and on the ground. In addition, cockpit procedures would be updated to put more emphasis on crew members other than the senior pilot.

ALL PHOTOS FROM THE ASSOCIATED PRESS