On 4 May, 1949, Italian club Torino was returning from a friendly match against Benfica in Lisbon, when on the approach to Turin, their plane lost height and crashed after clipping a wall close to the Basilica in the town of Superga, killing all 31 on board.
Apart from interruptions in the war Torino had won the Serie A championship for five consecutive seasons between 1943 and 1949, They would have probably been the main rivals to the great Real Madrid team of the 1950s. In one international they had supplied 10 of the 11 Italian players. The crash decimated the entire AC Torino squad, save one player who was injured and so didn't travel.
http://www.youtube.com/watch?v=JEuhGNtfJrw&feature=related