In one early morning, I am doing multi tasks. I think I am in the sub site but actually I am in the top level. When I deleted that site, some calls coming in.
Fortunately, there is PowerShell cmd you can restore deleted site collection.This cmdlet was introduced in Microsoft SharePoint Server 2010 with Service Pack 1 (SP1) and Microsoft SharePoint Foundation 2010 with Service Pack 1 (SP1).
Run Use Get-SPDeletedSite to find Identity (GUID) then
Restore-SPDeletedSite -Identity 610857cb-8414-4a89-8bf3-ad3628f6c86c
All deleted sub site can be retrieved from Site Recycle Bin!
Click the Site Collection Recycle Bin (Site Actions > Site Settings > Recycle Bin) under Site Collection Administration:
Select “Deleted from end user Recycle Bin”
Select the checkbox next to the site to restore and click “Restore Selection” from the menu above. Once completed, navigate to the newly restore site:
Thanks Microsoft for saving my job!