  The occurrence of workplace accidents is described within the context of
self-organized criticality, a theory from statistical physics that governs a
wide range of phenomena across physics, biology, geosciences, economics, and
the social sciences. Workplace accident data from the U.S. Bureau of Labor
Statistics reveal a power-law relationship between the number of accidents and
their severity as measured by the number of days lost from work. This power-law
scaling is indicative of workplace accidents being governed by self-organized
criticality, suggesting that nearly all workplace accidents have a common
underlying cause, independent of their severity. Such power-law scaling is
found for all labor categories documented by the U.S. Bureau of Labor
Statistics. Our results provide scientific support for the Heinrich accident
triangle, with the practical implication that suppressing the rate of severe
accidents requires changing the attitude toward workplace safety in general. By
creating a culture that values safety, empowers individuals, and strives to
continuously improve, accident rates can be suppressed across the full range of
severities.
