Abstract On 11 March 2017, a large fire ravaged through the Imizamo Yethu informal settlement in Cape Town, South Africa, killing four people. A total of 2194 informal dwellings were destroyed, and over 9700 people were displaced. This paper presents an analysis of the spread of the fire and factors that contributed to the conflagration. This work is based on interviews with the firefighters that responded to the incident, the disaster management incident log of the day, photographic evidence from various sources, reports in the public domain and site visits. Over 170 firefighters drawn from across the City of Cape Town's Fire and Rescue Services battled for over 13.5 h to put out one of the largest fires to have happened in a South African settlement in recent times. The efforts by firefighters to tackle the fire were hampered by several factors among them, inaccessible or narrow driveways, the absence of sufficient water supply in the area, and certain community interactions. This work is novel as in the literature there is negligible data regarding fire spread analyses in informal settlements. This has hampered the development of evidence-based responses and fire safety interventions being developed, as it is sometimes unclear how to reduce fire spread. The rate of spread during the fire is approximately calculated. By understanding fire spread rates, community interactions and suppression challenges firefighting strategies, engineering designs and municipal responses to this problem can be enhanced.