Often referred to as " Sewer Socialists , " these Milwaukee Socialists were characterized by their practical approach to government and labor . These practices emphasized cleaning up neighborhoods and factories with new sanitation systems , city owned water and power systems , and improved education systems . During this period , socialist mayor Daniel Hoan implemented the country 's first public housing project , known as Garden Homes . The socialists ' influence began to dwindle in the late 1950s amidst the " red scare " . On November 24 , 1917 , Milwaukee was the site of a terrorist explosion when a large black powder bomb exploded at the central police station at Oneida and Broadway . Nine members of the department were killed in the blast , along with a female civilian , Catherine Walker . It was suspected at the time that the bomb had been placed outside the church by anarchists , particularly the '' Galleanist '' faction led by adherents of Luigi Galleani . At the time , the bombing was the most fatal single event in national law enforcement history , only surpassed later by the World Trade Center terrorist attacks on September 11 , 2001 when 72 law enforcement officers representing eight different agencies were killed
World Trade Center terrorist attacks
September 11 attacks
History of Milwaukee