Contemporary disaster investigation reports into the Shuttle, Three Mile Island, or the World Trade Centre did not happen by chance, but were the result of an evolution of the discourse communities involved with investigating technological accidents. The relationships of private companies, coroners, outside experts, and government investigators all had to be developed and experimented with before a genre of investigation reports could exist. This book is the story of the evolution of these investigation discourse communities in published reports written between 1833 and 1879. Using the reports generated by seven different accidents on railroads and steamboats between 1833 and 1876, it is possible to observe the changes in how these reports interacted and changed over the course of the nineteenth century: The Explosion of the Steamboat New England in the Connecticut River, 1833; The Explosion of the Locomotive Engine Richmond near Reading Pennsylvania, 1844; The Explosion of the Steam Boat Moselle in Cincinatti, 1838; The Camden and Amboy Railroad Collision in Burlington, New Jersey, 1855; The Gasconade Bridge Collapse on the Pacific Railroad in Missouri, 1855; The Eastern Railroad Collision in Revere, Massachusetts, 1871; The Ashtabula Railroad Bridge Collapse in Ohio, 1876