First read How to Structure a Speech or Presentation for an understanding of how to approach your speech or presentation structure.
Introduction – Show what happened and clarify the damage/costs
People probably already know the bad news. That shouldn’t be the focus of the presentation, so summarise it in the introduction and make sure everyone understands both why and how it’s bad. Concentrate on the facts of the case. Facts and evidence. Costs, casualties, corollary damage.
Act 1 – Explain how & why it happened – legal advice needed
Provide context and explanations (rather than excuses). Take legal advice to avoid making any silly mistakes, but in general don’t apportion blame or make any unsound claims (i.e. use your common sense). Answer the questions your audience has (either find out what they are before you stand up, or ask for them here).
Act 2 – Show interim steps put in place to limit/contain damage
Explain what you’ve done so far, and the things you’ll be doing in the short term. Address these points in order of importance.
Act 3 – Explain the path to a permanent ‘fix’
Cover all of the important things which need to be done, in order of importance. Be sure to relate these actions, when necessary, back to the issues you identified in Act 1. Which mistake will this rectify, and how?
Conclusion – Who is responsible for ensuring the fix
Your audience needs a clear statement from you that lessons have been learnt. You’ve shown that by taking actions to resolve the issue, so point that out. Finish with a clear call to action for all parties involved in the ‘clear up’.