Marc-Vivien Foe, of Manchester City collapsed and died on the pitch during the semi-final of the Confederations Cup against Columbia, he was unchallenged in the centre circle, and was pronounced dead after some 45 mins of attempts to re-start his heart.
Story:
http://news.bbc.co.uk/sport1/hi/football/3024360.stm
Story:
http://news.bbc.co.uk/sport1/hi/football/3024360.stm