City on Fire chronicles the escalating danger of fire as a byproduct of progress in Mexico City in the modern era. By integrating urban environmental history with the histories of technology, science, and medicine, Anna Rose Alexander reveals how Mexico City changed in direct response to the growing threat of fire. By the mid-nineteenth century, efforts to modernize and industrialize the capital city had the unintended consequence of exponentially increasing the risk of fire and death, while also breeding a culture of fear. Through an array of archival sources, Alexander shows how fire became a catalyst for social change, as residents mobilized to confront the problem and their local officials. Advances in engineering and medicine soon fostered the rise of distinct fields of fire-related expertise. Conversely, the rise of fire-profiteering industries—such as insurance companies and manufacturers of extinguishers, alarms, was a detrimental side effect for many who could not afford or these services. Similarly, hydrants and water systems were concentrated in more affluent areas. City on Fire this demonstrates the evolving social inequity of fire risk in Mexico City; those most poor increasingly had the least access to fire safety resources and technologies.