The Washburn "A" Mill complex was the second-largest flour mill in Minneapolis, Minnesota. The original mill was built in 1874 by Cadwallader C. Washburn, but destroyed in an explosion in 1878, killing 18. The mill was later rebuilt, and for nearly 50 years, the Washburn "A" Mill was the most technologically advanced and the largest mill in the world. It was later shut down but now operates as a historical museum of the local milling industry. It is now called the Mill City Museum.