By the mid-nineteenth century, efforts to modernize and industrialize Mexico City had the unintended consequence of exponentially increasing the risk of fire while also breeding a culture of fear. Through an array of archival sources, Anna Rose Alexander argues that fire became a catalyst for social change, as residents mobilized to confront the problem. Advances in engineering and medicine soon fostered the rise of distinct fields of fire-related expertise while conversely, the rise of fire-profiteering industries allowed entrepreneurs to capitalize on crisis. City on Fire demonstrates that both public and private engagements with fire risk highlight the inequalities that characterized Mexican society at the turn of the twentieth century.