Following a terrorist bombing at the Canary Islands' largest airport, international traffic is rerouted to the much smaller airport at nearby Tenerife. As jumbo jets line up for take off, a thick fog settles in. A KLM 747 is given clearance to taxi down the runway and complete a 180-degree turn to prepare for take-off. With tragic consequences, a Pan Am 747 enters the same runway from the opposite end and moves straight into the path of the KLM jet.