Like Shakespeare's Hamlet, a tragedy of a later age that nonetheless resonates with the themes and conflicts of its Greek antecedent, we can summarize the conclusion of Antigone with the familiar pithy line - "everyone dies at the end."
Of course, this is not entirely true. Creon lives, but, as the other posts here have made clear, the other major figures die by suicide.
Perhaps the irony of the play's conclusion is found in the fact that the one figure that refused to obey the dictates of the gods is the only person left alive.
"[Creon] has a regard for the external forms of religion but no understanding of its essential meaning" (eNotes).
His life becomes one of suffering, as Creon loses his wife, his son and his rule in Thebes - all because he puts his self-interest above the gods interests.
Creon's transgression, ultimately, can be seen as the animating force behind Antigone's death. If she had been allowed to do her god-mandated duty and bury her brother, tragedy may have been avoided.
Antigone proclaims her innocence in this regard, saying, "You will remember what things I suffer, and at what men's hands, because I would not transgress the laws of heaven." The play ends with a statement from the chorus pointing blame directly at Creon, the sole survivor of the tragic events:
"There is no happiness where there is no wisdom;
No wisdom but in submission to the gods."
With Antigone, Haemon and Eurydice all dead by suicide, Creon is left alive to lament his folly and suffer his hard-earned wisdom.