Infrastructure is susceptible to damage from a large host of threats including natural hazards, aging and deterioration, and demands that increase with population growth and urbanization. These threats result in physical damage, as well as cascading social, environmental, and economic impacts that impair sustainability. A scientific approach is needed to mitigate risks posed by multiple threats while balancing broader objectives of sustainability. Therefore this research proposes a new model, “Sustainable Solutions for Infrastructure Subjected to Multiple Threats” (SSIMT), that evaluates the effects ofmultiple threats on system reliability while taking into account sustainability implications when selecting alternative design or upgrade solutions. The results offer new understanding of the risks posed by multiple hazards and the synergies or tradeoffs in protecting infrastructure from different hazards. Furthermore the analysis techniques offer effective strategies to jointly consider cumulative damage (e.g. from aging) and punctuated damage (e.g. from natural hazards) when assessing the influence of design or upgrade decisions that may mitigate risks from multiple potentially competing hazards. Finally, this presentation illustrates the application of SSIMT for comparing and selecting bridge retrofit and repair strategies that not only improve infrastructure performance under multiple threats, but also enhance life-cycle sustainability measures, such as cost, emissions, and embodied energy.  The results help to uncover the relationship between hazard resilience and sustainability of infrastructure, and guide the selection of optimal solutions which enhance sustainability while ensuring public safety.