The document analytically studies the behavior of a G+10 reinforced concrete building subjected to progressive collapse using ETABS software. It involves modeling the building in ETABS, performing pushover analysis to identify critical columns, and analyzing the structure's response to the removal of different columns according to GSA guidelines. The results show increased axial loads in surrounding columns and the formation of plastic hinges after column removal. The study determines the critical columns in each seismic zone and provides preventive measures to avoid progressive collapse of the building.