Progressive collapse, which frequently has disastrous results, is the term used to describe a structure’s breakdown spreading past the original site of damage. Diagrid systems are advantageous structurally and aesthetically due to their diagonal grid construction. With an emphasis on structural reactions after crucial columns are removed, this study examines how diagrid systems of square, rectangular and L geometry behave in progressive collapse scenarios. With the use of ETABS software, the structural system is modelled using in-depth numerical simulations and analytical techniques in compliance with the General Services Administration’s (GSA) requirements, which offer standards for building buildings that can withstand progressive collapse. The Demand Capacity Ratio (DCR), an essential tool for evaluating the safety margins and load redistribution capacity of structural elements following localized failures, is used to gauge how effective diagrid systems are. The findings show that, square geometry is more resistant to progressive collapse compared to other two geometries. This study emphasizes how important sophisticated modelling methods and DCR assessments are to creating strong building designs that can endure unanticipated structural breakdowns.