STUDY OBJECTIVES--The aim was to explore the pattern of disease in staff associated with a bomber that crashed in 1968 when carrying nuclear bombs. DESIGN--The database was constructed from staff files of Danish workers employed from 1 April 1963 to 1 July 1971. Comparison was made between subsequent mortality and hospital admissions of workers employed during the clean up of the crashed bomber, and those employed outside this period. SETTING--The study involved workers employed at Thule US air base in Greenland. MAIN RESULTS--During 1963-1971, 4322 staff were employed at the air base. Of these, 4265 (98.7%) were identified in 1987, among whom 1202 workers were employed during the clean up period. No differences were found in total mortality, or mortality from cancer, heart disease, or accidents, after allowing for differences in age, marital status, or length of employment, between those employed during the clean up period and those employed at other times. Similarly, no difference in hospital admissions between the two groups was found. CONCLUSIONS--No harmful effects on health due to the crash were found, as measured by mortality and hospital admissions.