Abstract: At approximately 1:20 p.m. on February 17, 2006, Employee #1, an apprentice electrician, and a coworker were performing maintenance on a 16,000-volt circuit breaker. The employees noticed that two fans on Bank Number 1 were not functioning. The guard on the fan was made of 0.25 in. diameter steel and had an approximately 5.375 in. by 1.5 in. opening. The fan tip to the guard's outer perimeter was 0.75 in., whereas the fan tip to the guard's outer face had a 1.75 in. measurement. . Employee #1 decided to gather nameplate date information on one of the transformer fans. The coworker went to obtain a pad of paper, so as to write down the retrieved information. As Employee #1 ascended the ladder, he inadvertently slid his left hand under the transformer cooling fan guard and his thumb made contact with the rotating fan blade. The fan blade amputated his thumb. Employee #1 was transported to a medical center where he was treated for his injuries and hospitalized.