On March 24, 1998, a crew of eight rural firefighters were burned over while attempting to suppress a backburning sector of the Bucklands Crossing Fire in North Otago, New Zealand. The fire demonstrates how factors typical of the New Zealand fire environment - steep slopes, highly flammable shrub fuels, and a strong foehn wind effect - combined to produce extreme fire behaviour. Several firefighters sustained varying degrees of injury. They were hit by a blowup that was most likely caused by a rapid reburn through previously underburned shrub fuels. The exact trigger for upslope spread and transition to a crown fire was not definitively identified; however, it was most likely the result of strong winds and localised turbulence, combining with steep topography and highly flammable, preheated shrub fuels. The case study report prepared on this burnover describes the activities of personnel leading up to and during the incident in relation to the fire environment and fire behaviour. Possible causes of the blowup are reviewed, and observed fire behaviour compared to that predicted by available models. Particular emphasis is placed on the contribution and alignment of fire environment factors and their role in triggering fire behaviour escalation. Aspects of firefighter safety during the incident are also discussed, including the performance of protective clothing. The findings highlight the need for increased training of firefighters in fire behaviour and, in particular, greater situational awareness of the fire environment and indicators of extreme fire behaviour potential. The case study provides a number of lessons learned that have relevance worldwide.