The Topic Admin and the Team Admin can delete a Topic.
<PC/Web>
On the upper right corner of the Topic, select the [···] icon and choose [Delete].
<Mobile>
Once you are in the Topic, select the [...] icon on the upper right corner. In the Topic Info page, select [Delete] located on the bottom.
*The messages in the Topic will be deleted along with the Topic, and cannot be restored.
*The files shared in the Topic will not be deleted along with the Topic, so please remember to delete the files before you delete the Topic.