Abstract 
 
 Assessing the conditions that create a rockfall hazard is a realistic goal in efforts to reduce worker injuries related to rockfall incidents. If tunnel workers can properly assess the risks of rockfall, with appropriate technical and administrative controls, they can better mitigate the risks. To achieve this goal, the Root Cause Analysis (RCA) methodology can be considered as a risk assessment method. An effective risk assessment method should include the ability to observe variable ceiling conditions and assess how much potential they represent for injuring workers. RCA's ability to prioritize the risks associated with changing conditions provides significant benefits to anyone responsible for designing, approving, or installing controls that are reasonably repeatable and stabilize the ceiling or reduce the risk of material falling from the roof. Using the RCA methodology, this study presents a case analysis of the risks and causes of rockfall incidents in a metro construction project. This study explains the use of an RCA methodology that can help improve system-level failures and weaknesses, such as rocks falling from the ceiling of a tunnel. It can be seen that personnel problems, management failures and information systems problems are now replacing technical failures as the focus of most accident analyses.