Delete a site collection in SharePoint 2013 using PowerShell
If you are deleting a SharePoint site collection, you may lose your all subsites under the site collection . When you delete a site collection, you permanently destroy all the content and the user information, as shown below.
- Documents and document libraries.
- Site configuration settings and user profile Service configurations.
- Groups, Role and security information, which is related to the website.
- Sub sites of the top-level website, their contents and user information.
To avoid any data loss, first try to take backup your site collection, then try these powerful commands.
SharePoint Nut-Shell 