According to the UN Refugee Agency, roughly 980,000 people live in the Cox’s Bazar region in Bangladesh, making it the largest and most densely populated refugee camp in the world. The number of fires in this settlement rapidly increased in 2021. On 22 March, a large fire event occurred, where 15 fatalities and 560 injuries were reported, and more than 9500 homes were affected leaving 45,000 homeless. This work seeks to reconstruct this incident based on firefighters’ statements, information found in the media, and satellite imagery. The study shows that (a) the fire spread extremely fast, with linear spread rates between 79 and 310 m/h and an average areal spread rate of 92,850 m²/h estimated, (b) the firefighters performed two main operations, firefighting and the creation of fire barriers, (c) the residents self-evacuated, deciding when and where to evacuate, and (d) the residents’ actions were similar to what has been observed in residential fires, with several people mentioning looking for missing family members. Fire spread is analogous to wildland fires where conflagrations spread across large areas of combustible material. This work can be used in planning for future large-scale fire incidents in tented camps, and proactively seeking ways of mitigating their impact. This is the first detailed documentation of such a large-scale refugee camp incident in the academic literature.

An aspect of human responses to fires is perceiving changes in intensity. The nature of fires can make this challenging, as flames and smoke are dynamic and change with time. For developing fires, this is in addition to growth occurring vertically and sometimes horizontally, with the footprint of the fire either remaining the same or increasing in size. The present study investigated how precisely humans could visually detect differences in the intensities and growth rates of simulated fires. Using a similar approach to research with non-symbolic visual quantities, a series of experiments compared the precision of judgments regarding which of two simulated fires was greater in intensity or growing faster in intensity when the footprint was fixed or varied. In addition, participants reported what characteristics they used to make their judgments. Precision was significantly worse when comparing the growth rates versus the intensities of fires, and it was better when the fire footprint varied. This provides initial estimates of the precision of mental representations of fire intensity and growth. In addition, participants reported using multiple characteristics, including the size of flames and smoke produced. The present study indicates that humans can precisely detect differences in the intensities of fires using visual cues, but have difficulty when comparing growth rates. We discuss how this suggests that the growth rate may not be a reliable visual cue used by occupants when responding to fires.