Workers, managers, occupational health and safety inspectors, and the general community can be trained to detect and promote action by the use of sentinel markers for detecting industrial disasters. A sentinel marker is a pre-disaster warning sign of impending failure in prevention. Administration sentinel markers are: weak occupational health and safety programs; lack of spontaneous access to top management; failure to accept responsibility for sub-contractors; absence of written disaster plans and drills for emergency response in the factory and in the adjacent community; non-investigation of prodromal leaks, exposures, spills, or injuries; punishment of “trouble-some” individuals (“whistleblowers”) reporting prodromal events; non-use or misuse of data on illness, injury, and absenteeism; and sub-optimal work conditions and supervision of shift workers. Information sentinel markers are: absence of worker and community right-to-know programs; non-use of data on earlier mishaps from similar technologies; and failure to provide toxicologic data to hospitals in the pre-disaster phase. Technological sentinel markers include the absence of fail-safe controls, interlocks, and automated alarm systems driven by real-time monitoring. Transportation sentinel markers include sub-optimal vehicle standards, alcohol and drug abuse, and fatigue in drivers. Preventive programs based on identification of all sentinel markers by workers and others outside a narrow spectrum of specialists are suggested to be more effective than are selective actions based on risk assessment analysis.