Did you know the deadliest airplane crash happened before the airplane ever had a chance to get off the ground?
Two 747s collided after a series of miscommunications led one to begin taking off–directly into the other.
Due to an explosion at an airport, a lot of flights were diverted to one of the Canary Islands.
One with a very small runway.
One of the airplanes (a Pan Am 747) missed their turnoff and was still on the runway. The other airplane (a KLM 747) mistook some instructions for takeoff clearance, and went to take off with the Pan Am flight still on the runway. The fog was thick, so the aircrafts themselves weren’t visible.
They collided, and over 500 people died.
I also found YouTube video that simulates what happened, including showing how thick the fog was on that day.
Ultimately, it was a case of bad conditions, an airport not used to this many airplanes, and ambiguous communication. In fact, the Pan Am flight knew what was happening, but so much communication was going back and forth that the message was missed by both ATC and KLM.
Here’s a ~20 minute documentary on the subject.
All of the Pan Am pilots survived.