Incident analysis physical conditions

The origin of the Domino Theory is credited to Herbert W. Heinrich, circa 1931, who worked for Travelers Insurance. Mr. Heinrich nndertook an analysis of 75,000 accident reports by companies insnred with Travelers. This resulted in the research report titled The Origins of Accidents, which concluded that 88 percent of all accidents are caused by the unsafe acts of persons, 10 percent by unsafe physical conditions, and 2 percent are Acts of God. His analysis of 50,000 accidents showed that, in the average case, an accident resulting in the occurrence of a lost-time work injury was preceded by 329 similar accidents caused by the same unsafe act or mechanical exposure, 300 of which produced no injury and 29 resulted in minor injuries. This is sometimes referred to as Heinrich s Law. Mr. Heinrich then defined the five factors in the accident sequence, which he identified as the Domino Theory. Heinrich s work is the basis for the theory of behavior-based safety, which holds that as many as 95 percent of all workplace incidents are caused by unsafe acts. See also Accident Chain Behavior-Based Safety. 

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