Smart infrastructureSmart infrastructure, underpinned by advanced technologies, holds immense potential to transform urban emergency responseEmergency response and crisis managementCrisis management. As cities worldwide transition toward smart urban ecosystems, the integration of real-time monitoringMonitoring, predictive analytics, and autonomous response systems has become a critical design priority. These developments promise to enhance the safety, resilienceResilience, and efficiency of urban environments, addressing the growing complexities of modern urbanization. However, the deployment of such smart infrastructureSmart infrastructure in emergency responseEmergency response is a high-stakes endeavor, demanding responsible and meticulous planning. This work introduces a three-tier integration framework that systematically transforms urban systems from isolated sensing networks to fully autonomous, self-healing operational architectures. Drawing on empirical case studies, including digital twinDigital twin implementations, the framework details the phased deployment of IoT sensing networks, AIArtificial Intelligence (AI)-driven analytics, secure communication architectures, and decentralized control systems. Critically, we delineate the boundary between routine emergency functions and high-threat defenceDefence augmentation, offering actionable insights and evaluation metrics for policymakers, urban planners, and technology developers. We argue that cities must adopt dual-use infrastructure strategies—systems that serve community functions during normal operations and transform into autonomous crisis coordination centers under conditions of natural disasters or deliberate attacks. Embedding resilienceResilience and adaptability at the design stage is no longer optional but a strategic necessity for future urban survival.