what are some players who have had premature deaths ? the top 4 i think all players know is 

Guyla Breyer, Henry Pillsbury, Sultan Khan, Daniel Noteboom

I think Pillsbury is famous.. but the rest I dont know.

Khan was c. 61.

Premature deaths of chess players would include Klaus Junge, Rudolf Chaousek, Gyula Breyer, Cecil de Vere, Georgy Agzamov, Julius Perlis, Harry Pillsbury, Edgar Colle, Lembit Oll, Guillermo Garcia, Alexander Zaitsev, Vera Menchik, Leonid Stein, and Abe Turner.  All died before they were 40.

Vera Menchik her career was considered long by a lot of players.

Klaus Junge (1924-45) played his last tournament when he was 18 years old, sharing first with Alekhine. He won with black against the World Champion in Salzburg 1942, but died in the war aged 21:

http://www.chessgames.com/perl/chessgame?gid=1013509

http://en.wikipedia.org/wiki/Klaus_Junge

Leonid Stein -

http://en.wikipedia.org/wiki/Leonid_Stein