http://en.wikipedia.org/wiki/List_of_ice_hockey_players_who_died_during_their_playing_careerGuess no one's gonna blame steroids now, huh?

4 already this year:
28 Tom Cavanagh[25] United States January 7, 2011 suicide[26] Played for the San Jose Sharks and the Springfield Falcons (AHL). Diagnosed with schizophrenia; found dead in the Providence Mall parking garage after jumping to his death.
23 Mandi Schwartz Canada April 3, 2011 acute myeloid leukemia Played for Yale University Bulldogs. Her younger brother Jaden was a St. Louis Blues first-round draft pick.
28 Derek Boogaard[27] Canada May 13, 2011 accidental mixture of alcohol and oxycodone toxicity Played six seasons and 277 games in the NHL, five with the Minnesota Wild and one with the New York Rangers, between 2005 and 2011.
27 Rick Rypien Canada August 15, 2011 suicide[28] Played 119 NHL games between 2005 and 2011. Rypien is also the cousin of former NFL quarterback Mark Rypien, Super Bowl XXVI MVP