Preparation speech

You are to prepare a 3-minute speech on the situation below. Bear in mind your position, your audience and your message in order to obtain your goal.

You are director of a school with a non-smoking policy. If anyone gets caught with a cigarette, they are expelled. One evening after hours students see you smoking a cigarette in your office. The next day students come to school carrying signs and you receive angry emails. During lunch you give a speech for staff and students to explain.