2002 Cadillac Deville ignition

I purchased this car used in January 2010, without a remote button to operate locking/unlocking of doors, trunk, etc. Until now I have had no issues. I drove the vehicle this morning then parked it in the drive. I just went to leave and there is a small peice of metal, inside the ignition, preventing me from inserting the key into the ignition. Any ideas what might have caused this or how to remedy it? Thank You.