A synechdoche is a figure of speech where a part of an object or a person is used to refer to the whole thing. For example, a fictional character may be described by one part of their body, such as their hands, which can come to define the character. For example, a famous example occurs in Hard Times by Dickens, when he refers to the labourers in the factories of Coketown as "Hands," which emphasises the impersonal way in which they are viewed and how they operate as cogs in a machine--key to what Dickens was trying to say about Industrialisation.
Now, I have looked through Ode 1 of Oedipus Rex with a fine tooth comb, but I can't actually find any reference at all to the murder of Laius, let alone an example of synechdoche that refers to it. There is of course much mention of "The fires of grief, the fires of darkness" and the calamity that Thebes is suffering, but nothing specifically about the murder. So either you have the wrong Ode or perhaps you are asking the wrong question. Sorry I can't be more help! You might just want to check your question and get back to us here on eNotes.