Beginning in 2006 with pioneering work on responses to the SARS crisis in global cities (and in particular Toronto, Hong Kong and Singapore) and expanding their work recently in the context of Covid‑19 and its link to suburbanization, S. Harris Ali, Roger Keil and Creighton Connolly have been working on metropolises and pandemics for the past 15 years. Their analyses help us to understand the current Covid‑19 crisis in its urban dimensions.