Up until fairly recently, shipwrecks were routinely blamed on storms or on the actions of the captain and crew. Today, regardless of whether the accident involves a grounding, collision, fire, or spill, investigators focus on both the immediate cause of an accident, and any underlying factors. In a recent report to the British government, retired admiral John S. Lang, chief inspector of marine accidents for the United Kingdom, summed up an investigator's role:

In the past many casualties were, in most people's minds, caused by a single event, often described as human error. This was a convenient means of concluding an investiga- tion; and it was all too easy to blame one person for whatever happened. Many companies did no more than dismiss the unfortunate individual and felt they had dealt with the problem satisfactorily. But no accident is ever caused by a single...