Worker fatalities related to confined spaces were examined. A total of 585 fatal incidents and 670 worker fatalities occurred in confined spaces between 1983 and 1993. An annual incidence rate of 0.08 deaths per 100,000 workers was calculated. The riskiest industries included manufacturing, agriculture, construction, transportation/communication/public utilities, and mineral/oil/gas. The common atmospheric causes of fatalities were hydrogen-sulfide (7783064), methane (74828), inert gases, and carbon-monoxide (630080), as well as oxygen deficiency. Numerous fatalities were attributed to mechanical asphyxiation, entrapment in grain and other agricultural products, and engulfment in sand, sawdust, and other building materials. From 1980 to 1989, a total of 572 trench cave ins claimed 606 lives, most of which occurred in the construction industry. Of a reported 1,018 poisoning deaths and 1,218 asphyxiation deaths, 27% and 25% occurred in confined spaces, respectively. Fatality Assessment and Control Evaluation investigators examined 70 fatal incidences, resulting in 109 deaths, related to confined spaces. The construction, public administration, and manufacturing industries accounted for most of the fatalities. About 80% of the incidences involved hazardous atmospheres, of which 43% were oxygen deficient. In 40% of the incidences, written safety procedures were established. Of the victims examined, 40% were repairing or maintaining the confined space and 36% were attempting to rescue a victim. Confined spaces such as tanks, vats/pits, digesters, and sewer manholes were frequently involved in fatal incidences. Only 6% of the victims received safety training specifically aimed at confined space entry. The implementation of a confined space program, involving confined space identification, warning sign postage, hazard and task assessment, entry, rescue, and monitoring procedure development, and employee training, was recommended. The authors conclude that the recognition of confined space hazards and the establishment of rescue protocols are important aspects of worker safety.