Before shifting blame on an unsuspecting party, it's wise to make sure you haven't missed anything. Yelling about how no one told you about X while there is an unread email in your inbox will quickly wear down your credibility.
Work from the assumption that you missed something first. Give each party involved leeway while you investigate. If it is found that you are at fault, take ownership and publicly state your efforts to prevent those mistakes in the future. If someone else dropped the ball, approach them individually. There is no glory in knowingly throwing someone under the bus.