Book excerpt: In the aftermath of catastrophes, it is common to find prior indicators, missed signals, and dismissed alerts that, had they been recognized and appropriately managed before the event, could have resulted in the undesired event being averted. These indicators are typically called "precursors." Accident Precursor Analysis and Management: Reducing Technological Risk Through Diligence documents various industrial and academic approaches to detecting, analyzing, and benefiting from accident precursors and examines public-sector and private-sector roles in the collection and use of precursor information. The book includes the analysis, findings and recommendations of the authoring NAE committee as well as eleven individually authored background papers on the opportunity of precursor analysis and management, risk assessment, risk management, and linking risk assessment and management.