(Oregon City, OR)  --  An investigation is underway after a Clackamas County family found a dead rabbit inside their mailbox.  Police say Olsen Bergman filed a police report Monday after a neighbor noticed the animal at her home just outside of Oregon City.  Bergman says the mailbox was a replacement that she installed Sunday after someone stole her entire mailbox on Saturday.  Several other neighbors have reported having their mail stolen.  Police are looking for a suspect.