Oedipus Rex by Sophocles , what led to his downfall?

"There is no man blessed amongst us. All the works of man are known and every soul is tried," sings the chorus at the beginning of Oedipus Rex. After answering the riddle of man, Oedipus becomes the foremost of living men and takes his turn on the top of the wheel. Oedipus believes, "it is better to rule over man than over a wasted place; since, a walled township is nothing if it is empty …

…the one he brings upon himself. The minute Oedipus made someone feel less, he became less. After observing his dead wife, Oedipus, receiving strength from Apollo, gauges out his eyes. Oedipus goes through suffering and becomes more heroic. For the first time he becomes concerned about his children and the life they will now lead because of what he has done. Lies smell of mortality; Oedipus' works are now know and every soul is tried.