Professional speaker Patricia Fripp suggests you have a close ready for your speech in case you need to suddenly stop your speech. This could be because you run out of time, your audience is restless, some disaster happens, etc. Whatever it is, when it happens, go immediately into your speech closing so you don't lose your audience's attention.
Still the same,
Tim Wilson
Professional Speech Coach
Free speaking tips at: http://speakingquicktips.blogspot.com