Events are caused. Typically, they are triggered by human action. In most cases, the human action causing the event was in error. However, the action could have been directed by a procedure; or it could have been a shortcut to get the job done—a violation. In any case, an act initiates the undesired consequences. On a plant-by-plant basis, experience has shown that significant events tend to occur every few years, but no law of nature says they must. The cycle can be broken, but only by understanding how events come about through human error. The Anatomy of an Event provides a picture (see illustration) of the elements that exist before an event occurs. Breaking the links will prevent events.