An investigation was made by NIOSH of two robot related deaths of workers, one an operator of an automated die cast system, and the other an operator of an automated machine system. A common factor in these two deaths was that the victims had entered the safeguarded area of the robotic workstation during automatic operation. Although both work cells were equipped with interlocked gates, the safety perimeters had openings which allowed worker access to the robots' work zone without stopping automatic operation of the robots. The victim in the first accident had finished his initial training 3 weeks before the accident while the victim in the second incident had 9 years of experience. The first victim was pinned between a steel safety pole and the back end of the industrial robot. The interlock barriers which were used in this case were easily bypassed. In the second case, entry into the robot work envelope was possible through two unguarded openings which were not equipped with interlocked gates or safety devices. In addition, only half of the bifold gate was equipped with an interlock. This worker had been previously struck by this same robot some months earlier when he entered the workspace, also against all safety rules, while the robot was in operation. The role of supervisors in the prevention of robot related accidents was discussed.