A sentinel event is "any unanticipated event in a healthcare setting that results in death or serious physical or psychological injury to a patient, not related to the natural course of the patient's illness".[1] Sentinel events can be caused by major mistakes and negligence on the part of a healthcare provider, and are closely investigated by healthcare regulatory authorities. Sentinel events are identified under The Joint Commission (TJC) accreditation policies to help aid in root cause analysis and to assist in development of preventive measures. The Joint Commission tracks events in a database to ensure events are adequately analyzed, and that undesirable trends or decreases in performance are caught early and mitigated.