The Great Mill Disaster (also known as the Washburn A Mill explosion) occurred in Minneapolis, Minnesota, United States, in 1878. The disaster resulted in 18 deaths. The explosion occurred on the evening of Thursday, May 2, 1878, when an accumulation of flour dust inside the Washburn A Mill (the largest mill in the world at the time) led to a dust explosion that killed the fourteen workers inside the mill. The resulting fire destroyed several nearby mills and killed a further four millworkers. The destruction seriously impacted the city's productive capacity for flour, which was a major industry in the city. Following the blast, Cadwallader C. Washburn, the mill's owner, had a new mill, designed by William de la Barre, constructed on the site of the old one. This building was also later de