This paper presents progressive collapse simulations to assess the robustness of a seismic-resistant building using self-centering moment resisting frames (SC-MRFs) under a sudden column loss scenario. The first floor of the building, including the composite floor, was modelled in ABAQUS using a mixture of finite element types and simulation methods to balance computational cost and accuracy. First, key components of the numerical model, including the composite beams, the fin-plate beam-column connections, and the perimeter SC-MRFs, were validated against available experimental results to ensure a reliable simulation. The validated model was then used to study the robustness of the building under a sudden column loss event. Both nonlinear static and dynamic analyses were employed. The simulations allowed for the identification of all possible failure modes and the quantification of the contribution of the composite floor to the robustness of the frame. The results show that the building can withstand the code-prescribed load with a safety factor of 2 and that the structural limit state that triggers progressive collapse is the buckling of the gravity columns. The Dynamic Increase Factor (DIF) was also identified by comparing the static and dynamic responses.