A study of excavation cave in fatalities in the construction industry was conducted. Abstract reports of 120 accidents involving fatalities that occurred at construction sites nationwide in the United States during the period 1974 through 1981 were obtained from the investigative files of OSHA and reviewed. All cave in accidents were analyzed according to the soil classification system devised by the National Bureau of Standards (NBS) and NIOSH. Eighty five accidents were identified as cave ins. These resulted in 92 fatalities. All fatally injured workers were male and their average age was 37 years, range 15 to 70 years. Occupations were listed for 73 workers. Of these, 52 percent were laborers, 18 percent were pipelayers, 14 percent were supervisors, and 10 percent were plumbers. Sixty four cave ins occurred at excavation sites with vertical walls, 17 with sloped walls, and four with combined vertical and sloped walls. The average depth of the excavations with vertical walls ranged from 5 to 25 feet (ft), average 11.2ft. Sixteen of the cave ins involving sloped walls did not meet the NBS/NIOSH recommendations for sloping. Only nine vertical walled excavation sites had some type of shoring system in place. Of these, employees were not working within the confines of the shoring system at seven sites at the time of the accident. A total of 103 citations were issued by OSHA in connection with the accidents. The most frequently issued citation dealt with inadequate sloping, shoring, sheeting, and bracing. Other citations concerned storing excavated material too close to the edge of the excavation and not providing adequate protection against vibration sources. The authors conclude that cave in fatalities at excavation sites apparently result from a lack of shoring or inadequate sloping. These may be prevented by using economic incentives, enforcing excavation standards, and applying criminal penalties for willful violations of safety and health standards.