I discovered a way to do this a while back. If it is a topic that you started, you can scroll down to the bottom of the page, and underneath the last post, there will be a link that says "Show moderation tools". If you click on this, a button appears on the left side of the page that says "Topic Moderation". If you click on this button, a drop - down list will appear. There is only one option - "Delete this topic". Click on it, and a confirmation screen should appear warning you that the topic will be deleted and that there will be no more warning screens. Confirm that you want the topic deleted, and it should be gone. Hope this helped!