How do I delete a topic?
Go to Forums.
Select the Forums tool from the Tool Menu of your site.
Select Delete Topic from the drop-down menu.
Click the More link next to the topic you want to delete, then chose the Delete Topic option from the drop-down menu.
You can also click on the title of a topic to select it.
Then click Delete Topic from within that topic.
The Delete Topic button is located at the top of the page below the course name. This will erase the topic and all conversations on the topic from its particular forum.