Now we see the critical link of property damage incidents, which were unidentified in Heinrich's estimates. It's likely the base number is much larger than 600. But notice the dramatic difference between the two ratios. Suppose the number of minor injuries in Bird's ratio was multiplied by a factor of three to make it comparable to the 29 minor injuries in the Heinrich ratio. Then you would have 1,800 near misses and 90 property damage incidents per 30 minor injuries.
Property damage is a physical trace of an incident, and the precursor of an injury.
These damages need to be investigated and repaired. Proof positive Let me tell you a true story to illustrate how focusing on property damage can make a difference. Walking along a scaffold, a worker slipped on a metal plate and almost fell several stories to his death. Fortunately, he was able to pull himself back onto the walkway. The safety committee didn't simply blame the welder responsible for securing the plate.