Crosby is a city in Crow Wing County, Minnesota, United States. The population was 2,299 at the 2000 census. It is part of the Brainerd Micropolitan Statistical Area. Crosby is adjacent to its twin city of Ironton. It is one of the cities in the Cuyuna Range. In the 1932 local elections, the voters of Crosby elected Karl Emil Nygard as President of the Village Council and thus became the first city in the United States to have a Communist mayor. Crosby was the location of the worst mining disaster in Minnesota, the Milford Mine disaster. On February 5, 1924, a new tunnel was blasted too close to nearby Foley Lake, and water rushed in, killing 41 miners.