http://www.myce.com/news/outlook-2013-bug-deletes-inbox-contact-calender-on-empty-trash-62532/
With the recent release of Office 2013, Microsoft has introduced an unbelievably stupid bug to Outlook 2013. Several users on the Microsoft support forums report that when they emptied their deleted items folder, they lost their entire inbox, their contacts, notes and calender items. Even worse, nothing can be recovered, not even using the ‘Recover deleted items option’.
Outlok 2013 - Empty Deleted Items deletes everything from mailbox?