The importance of workshift as a mine accident risk factor has not been fully explored in any readily available analysis of national mine safety. This study begins to correct that deficiency by presenting frequency distributions of fatal and lost-time injury accidents segregated by workshift and elapsed time into the shift as experienced by US coal mine workers for the years 1978 to 1980. Variables of interest in the current analysis include time of accident, shift, mining method (i.e., surface vs underground), degree of injury (i.e., fatal vs lost-time), victim age, job title, nature of injury, machinery victim was operating or handling at the time of accident and source/nature of injury. 3 refs., 8 figs., 2 tabs.