The study presented in this research is a systematic human factors approach comparing two striking process accidents in Latin America: the Copiapó mining accident (2010), at the San José copper-gold mine, in Chile, and the FPSO CSM accident (2015), at Camarupim offshore oil field, in Brazil. Despite being different industrial segments - mining and O&G - more similarities than differences were observed in the treatment of process safety anomalies, especially those related to major accidents. The intense interactions between workers, equipment and processes, in both industries, have been making significant developments in the edge of innovation and technology, however increasing the complexity of risks in the workplaces. Furthermore, the differences between the preparation and handling of emergency situations show how complex, and critical, process safety is in these industrial areas. Aiming to adequately evidence how this complexity is intrinsically part of the various system that form the entire process, the FRAM (Functional ResonanceAnalysis Method) was utilized to model and analyses both accidents, under a human factors approach. Interactions and interrelations between LOPC, non technical skills, resilience and technical procedures were noticed as crucial for process safety and productivity of daily operations, as well as the preparedness for emergency situations.