Tiresias informs Creon that Polynices's body needs to be buried in order to appease the gods and shield Thebes from their wrath, and that Creon is at a turning point in his life. a significant sign that portends Creon's demise.
How does Tiresias warn Creon?
Teiresias foretells Creon's demise by telling him that Thebes will suffer civil unrest and personal tragedy as a result of Creon's refusal to bury Polyneices and his imprisonment of Antigone alive.
The main omen that Teiresias alerts Creon to in "Antigone" is the terrible results of Creon's deeds. "You have entombed a living soul and sent below a denizen of earth, and you have wronged the nether gods by leaving here a corpse unlaved, unswept, and unsepulchred," Teiresias tells Creon, "in quittance of thy murder, life for life."