Urban planning is a progressive endeavor. Planners strive to improve cities, to make them more equitable, beautiful, sustainable, and resilient. This aspirational quality reveals a particular orientation towards time—a culture of ‘progressive futurity’ at the core of the profession, animated by visions of desirable urban futures and strategic claims about how these might be reached. Although planners in the United States rarely talk openly about ‘progress,’ an intrinsic progressivism remains in American planning. Without it, planning’s identity and legitimacy would disappear. This dissertation examines how this progressive futurity confronts a slow crisis of urban decline. It follows the City of Detroit’s urban planners as they grapple with the consequences of population loss, economic collapse, and infrastructural decay. I suggest that the magnitude and duration of Detroit’s decline—stretched across the planners’ careers—has steadily eroded their capacity for, and their faith in, effective planning interventions. As a result, their working relationship to the future bears little resemblance to the progressive futurity of the wider profession. Instead, Detroit’s planners routinely engage with the future in deeply personal, human ways, through a ‘phenomenological futurity’ of uncertainty, fate, despair, and hope.