Whenever a creature dies, that creature's controller may draw a card.
In a multiplayer game, if a player loses the game, triggered abilities that player controls are removed from the stack and no more from that player can be added. This means that if a creature an opponent controls dies while you control Fecundity, and you lose the game before Fecundity’s triggered ability resolves (perhaps because you lost the game at the same time that the creature died), that player won’t draw a card.