One of the ironies of "The Cask of Amontillado" is that Fortunato contributes to his own end. In what ways does he do so?

In Poe's "The Cask of Amontillado," Fortunato contributes to his own death mainly through his inebriation. The narrator has "borne as best [he] could" "the thousand injuries of Fortunato," and vows to get revenge. He encounters Fortunato, an aficionado of wines, during the "carnival season"; he is dressed as a jester. By promising him rare wine, the narrator lures the already-drunk Fortunato to his wine cellar. On the way, the narrator offers Fortunato wine to keep him pliable, and Fortunato cannot resist. The narrator chains Fortunato to a wall, and has no trouble due to Fortunato's state. After doing so, the narrator acts as though Fortunato is lagging behind in leaving, and Fortunato believes that he is joking. The narrator begins to build a wall enclosing Fortunato, using a trowel that he had shown Fortunato earlier as a masonic sign. In response to Fortunato's protestations, the narrator continues denying Fortunato's bondage or enclosure, and leaves Fortunato to die.