Ramstein Airshow - Frecce Tricolori - In one of the world's worst airshow disasters, three jets from the Royal Italian Air Force display team, Frecce Tricolori, collided in mid-air (two jets collided; one of these two jet collided another third one).
It happened during an airshow at Ramstein Air Base, Germany. One jet crashed into the crowd, while the two other crashed around the runway. Sixty seven spectators (as well as all three pilots) were killed and hundreds injured in the resulting explosion.