Madrid runway disaster
As the Boeing 727 taxied down runway 01, the DC-9 crew accidentally made a wrong turn in the fog and took their plane onto the runway, into the path of the 727. The 727 crew saw the DC-9 and tried to avoid it. the collision turning their planes to take off;  however, the 727 had not reached flying speed and its rear fuselage struck the DC-9. Both aircraft caught fire and were destroyed.