## 4 Conclusions  
Seismic sequences are likely to hit buildings and infrastructures in several active seismic regions in the world. Particularly, damage aggravation is a notable mechanism that could result in deficient behavior of both engineered and nonengineered buildings. Although considerable attention is paid to the mainshock-aftershock sequence vulnerability analysis of buildings and other structures, the foreshock-mainshock-aftershock sequence is barely considered so far. Thus, to replicate the likely scenario of earthquake sequence, we conducted fragility analysis of a representative low-rise SMRF building from a very active seismic active region, Nepal. We estimated capacity from the pushover analysis and demand for foreshock, foreshock-mainshock, and foreshock-mainshock-aftershock scenarios from nonlinear time history analysis. Fragility functions for all scenarios were created and compared. We conclude that the increase in vulnerability is more sensitive for post-foreshock exposure to mainshock than post-mainshock exposure to aftershock. This indicates that the foreshocks can initiate D1 damage state, and aggravation will take place rapidly due to the occurrence of mainshock. The occurrence of aftershocks is found to moderately increase seismic vulnerability of low-rise SMRF buildings. The duration of the occurrence of seismic sequence cannot be estimated; thus, the existing buildings are likely to be exposed to the sequence without strengthening immediately after a seismic event. To this end, damage aggravation is certain to occur. Therefore, the existing seismic codes should incorporate the effects of seismic sequence to ensure target performance level in buildings, especially in the regions where some of the active faults are proven to result in seismic sequences that last a long time. We considered engineered construction to assess the performance of low-rise SMRF buildings, which possess adequate stiffness; however, damage accumulation can be severe in the case of ordinary moment-resisting frame buildings as well as non-engineered constructions. Thus, there lies an opportunity to quantify seismic vulnerability of both construction types. The time histories selected for nonlinear dynamic analysis are taken only up to 0.47 g PGA; meanwhile, higher values of PGA can result in damage saturation even during the foreshock-mainshock sequence. Thus, considering seismic sequences having high to very high PGA can improve the understanding of damage aggravation and saturation. The sensitivity due to foreshock, mainshock, and aftershock ground motion can be considered in future research to assess the variation in displacement demand. This could provide insights regarding the variation in seismic vulnerability due to variation in strong motion characteristics between foreshock, mainshock, and aftershock. Apart from this, micro-modeling can capture more local mechanisms that could help define damage extent and aggravation extent. Future research can consider the impact of the foreshock-mainshock-aftershock sequence in high-rise RC buildings and other structures and the benefit of implementing mitigation measures to reduce seismic vulnerability. Conceptualization, D.G. and R.A.; methodology, D.G., P.P., A.F. and R.R. ; software, P.M.; validation, R.A. and D.G. ; formal analysis, P.M.; resources, D.G. and R.A.; writing--original draft preparation, P.M. and D.G. ; writing--review and editing, P.P., R.A., A.F. and R.R. ; visualization, D.G., A.F. and R.R. ; supervision, D.G., R.A. and P.P. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. **Acknowledgments:** The authors sincerely thank [PERSON] for sharing an image showing progressive damage.