The  study  aims  to  investigate  the  progressive  collapse  behaviour  of  RCC  building  under extreme  loading  events  such  as  gas  explosion  in  kitchen,  terroristic  attack,  vehicular collisions  and  accidental  overloads.  The  behavioural  changes  have  been  investigated  and node displacements  are computed when the building is subjected to sudden collapse of the 
load bearing elements.  Herein, a RCC  building  designed based on Indian standard code of practice  is  considered.  The  investigation  is  carried  out  using  commercially  available software. The node displacement values are found under the column removal conditions and collapse  resistance  of  building  frame  is  studied  due  to  increased  loading  for  different 
scenarios.  This  simple analysis  can be used to quickly analyse the  structures  for  different failure conditions and then optimize it for various threat scenarios.