Spassky Misses the Draw

In 1972, Robert Fischer and Boris Spassky played for the world chess championship.  The 13th game featured a complicated endgame.  On move 69, Spassky missed the drawing line and went on to lose the game, the match, and the world title.  Fischer sacrificed a piece for three pawns to get to this endgame.  By move 69, it was a clear draw.  However, Spassky was short of time and probably exhausted and missed  the drawing line.  Fischer was able to run his passed pawn down the board.