Studies have been carried out so as to gain an understanding of the behaviour of structural steel members exposed to different degrees of corrosion and high temperature in service. The progressive collapse and buckling characteristics of tubular members subjected to high temperature together with corrodants (localised corrosion) are presented in this paper. A microstructural analysis has been carried out so as to understand the change in mechanical and chemical properties that has been brought about in the material. The results reveal that the failure of the corroded members is attributed to localised axisymmetric imperfections imparted to the tubular members apart from loss of weight. The failure of members subjected to elevated temperature is attributed to the coarsening of the grain size.