TY - JOUR AB - Purpose– The Donner expedition to California in 1846‐1847 is one of the darkest tales of the great migrations west. While much has been written about the tragedy, a group analysis based on business research has not been undertaken. The purpose of this paper is to suggest that the story of the Donner Party is primarily a group failure, with implications for practicing managers employing temporary groups in uncertain situations.Design/methodology/approach– Group theories concerning the nature of temporary work groups, interdependence, diversity, social identity, and leadership are employed to explain how negative group processes likely contributed to the disaster.Findings– Based on books and a film about the incident, the Donner Party suffered a social breakdown based on: the changing nature of the goals of the expedition in mid‐course, which is difficult for temporary teams to handle; destructive forms of diversity based on cultural background and social status; and a lack of critical skills and effective leadership. The story also illustrates that small, cohesive groups had a better survival rate than individuals.Research limitations/implications– While only a single case, this study demonstrates the special nature of temporary groups and demonstrates that not all diversity is positive. Both issues require strong leadership. Furthermore, the study demonstrates the importance of considering context in group research.Originality/value– This is an original analysis of the Donner Party using group theories. This study reminds managers of the fragility of temporary groups, and stresses the need to consider the possibilities of accidents/disasters when undertaking large projects. VL - 17 IS - 4 SN - 1751-1348 DO - 10.1108/17511341111164436 UR - https://doi.org/10.1108/17511341111164436 AU - Patton Eric PY - 2011 Y1 - 2011/01/01 TI - When groups fall apart: the Donner Party disaster T2 - Journal of Management History PB - Emerald Group Publishing Limited SP - 435 EP - 450 Y2 - 2024/04/25 ER -