Having suggested that current understanding of site safety roles is a problem within the construction industry, this paper now at-tempts to reduce the problem by analyzing the ability of each entity that plays a major role on construction sites to influence the root causes of accidents. This theoretical analysis is based on a review of pertinent literature and the writer’s training and experience as a construction project manager, expert witness, and authorized OSHA instructor). It is suggested here that all construction accidents result from one or more of the eight root causes listed in Table 2. Many of these causes are similar to those proposed by Abdelhamid and Everett (2000) and Suraji et al. (2001). Because they are behavioral, they differ substantially from the physical porcess root causes discussed by Hinze et al. (1998).