To troubleshoot Active Directory object deletion issues, here is a list of steps you can take:
Check the Deleted Objects container: Look for the deleted object in the Deleted Objects container. If the object resides there, you can attempt to undelete it or you can use the tombstone lifetime value to determine if it is still available
Check Event Viewer logs: By reviewing the event logs, you can determine the time and user account that deleted the object
Use LDP.exe: The Lightweight Directory Access Protocol (LDAP) data editor allows you to undlete the object if it is available in the Deleted Objects container
Check permissions: Review NTFS and Active Directory permissions to ensure that the user had the proper permissions to delete the object
