Abstract: Three employees were replacing a fuse in a 480-volt, 100-ampere Spectra Series General Electric panelboard. None of the employees had been trained for this procedure nor were they wearing personal protective equipment of any kind. The fuse box was about 1.5 meters above the floor. During the operation, the fuse failed, and one of the metal ends of the fuse became lodged between the terminals two of the in-coming conductors. This caused an electrical fault. The ensuing electric arc burned the three employees, who were standing about 1 meter from the panelboard. Employee #1 sustained third degree burns from his waist up and was placed on life support. The other two employees sustained third degree burns on their faces, shoulders, and chests. All three employees were hospitalized for their injuries.