In recent years, cities are under increasing pressure to transform education, health care, transportation, civic engagement, public safety as well as other government services to maintain their competitiveness and improve citizen’s quality of life. This transformation is known as “smart city” initiatives. Broadband network infrastructure is an important underlying infrastructure for smart city projects. This study investigates risks in municipal broadband projects led by local government. Our goal is to develop a middle range theory to explain risks and their interrelationships. We first used grounded theory to identify a set of risks from archival and interview data. Next, we used revealed causal mapping analysis to develop a model of risks and their linkages. Our results suggest five risk categories: socio-political risks, approval risks, financial risks, technical risks, and partnership and resource management risks. We also found that several risk categories are intertwined. In particular, socio-political risks have impacts on other risks. Therefore, risk management and risk mitigation strategies need to take a holistic view towards all risks and their interconnections instead of focusing on each type of risks in isolation.