Many organizations believe that occupational accidents and resulting injuries are caused by some short coming on the part of the individual worker. The Domino Effect Theory of accident causation proposed by HW Heinrich may explain the justification for this. Preventable injuries culminate from a series of sequential events, as represented by five dominos. The first represents the task or situation, followed by some faulty worker decision, resulting in the unsafe action, which leads to an accident and the inevitable injury. By tipping the first domino all tend to fall, and by removing some of the intervening domino the accident can be eliminated. Hence the belief that workers decisions or actions are the primary cause of accidents.
The findings of two major research studies supported this conclusion. The first by Heinrich in 1931 where he analyzed over seventy thousand accidents. He found that: