The book traces the emergence of the "accident" as a marginal misfortune in modernist thought, and its transformation into a "preventable" misfortune in the late 20th century. It identifies accidents as being crucial to self-conscious, rational modernity in the early 20th century: accidents which "just happen" marked the limits of rational explanation and only the irrational denied their existence. However, as an examination of contemporary medical and health promotion writing shows, the accident should no longer happen. The rise of risk assessment constructs the accident as an essentially preventable misfortune.