This thesis investigates the robustness of reinforced concrete (RC) structures subjected to local damage scenarios, with particular attention to the sudden loss of a supporting column. The research focuses on the progressive collapse response of RC beam-column subassemblages and related structural systems. The structural behavior after column loss is not governed by a single mechanism, but by a progressive sequence of resisting actions. At small displacements, the response is mainly controlled by flexural action, where bending resistance and plastic hinge formation dominate. At large displacements, after flexural and arching mechanisms degrade, catenary action may become the dominant resisting mechanism, with tensile forces in the longitudinal reinforcement providing residual resistance.