Sudbury police are trying to determine if a device a man used in a robbery is really a bomb.  On Wednesday a man went into the Northern Credit Union in Capreol  just before closing time and told the employee he had a bomb strapped to himself.  He then robbed the workers and took off in a small car.  The man said he was carrying out the robbery because he had just lost his job.  He left the device behind and the bomb squad rendered it inoperable.  No one was hurt and police are looking for the man.