Abstract: At approximately 7:00 a.m. on April 1, 2003, Employee #1 and three coworkers arrived at the hospital work site and obtained security clearance from hospital personnel for access to the switchgear room. The crew consisted of four employees: two journeymen electricians (including the foreman) and two electrical apprentices (including Employee #1). One journeyman electrician and Employee #1 stayed in the switchgear room and the other journeyman electrician and apprentice went to the MRI room. The crew in the switchgear room removed the lower panel cover to the circuit breaker dead front externally operable panelboard, the vertical side panel on the right side of the panelboard, the front breaker cover, and the panel covering the cabinet to the right of the disconnect panel. The MRI circuit breaker was the lowest one on the right side of the panel, and the cover to enclose it was one of the panels removed. The breaker for the MRI in the switchgear room was opened to de-energize the MRI. The journeyman electrician in the switchgear room radioed to the electrician in the MRI room to confirm the power was disconnected, and received notification that it was. The journeyman electrician in the switchgear room then traced the wires for the MRI to their locations on the neutral and ground buss. Once all the wires were located, the journeyman electrician in the switchgear room started disconnecting the MRI wires connected to the breaker while Employee #1 started disconnecting the wires connected to the busses. At the same time, the electrician and apprentice in the MRI room started disconnecting the service wires from the breaker located there and disconnecting the wires leading from the circuit breaker to the power conditioner for the MRI because a new conditioner was also being installed. While the journeyman electrician in the switchgear room disconnected the MRI wires from the circuit breaker, Employee #1 removed the neutral and ground wires which were connected to the upper ground buss. He started disconnecting the farthest left wire first, which was marked with green tape. According to the journeyman electrician, this wire was connected about mid-way between the far left and right side of the buss. This wire was loosened and removed from the lug, and then guided out of the cabinet. By this time the journeyman electrician had two wires disconnected from the breaker, with one more to go. Employee #1 then started working on the second wire connected to the ground buss. This wire was marked with green and yellow tape and connected to the buss slightly to the right of center on the buss. As before, he used an Allen key with a handle to loosen up the first lug and wire. After the lug was loosened, he removed the handle to the allen key and loosened the lug a little further using just the allen key. Employee #1 was holding the Allen key in his left hand when he grabbed the wire and lifted it straight up to remove it from the lug and, in so doing, contacted the energized buss. An arc/flash occurred that caused both the electrician and Employee #1 to go blind momentarily. When the arc subsided, the electrician regained his vision within a few seconds and reached for the door to the switchgear room, which was slightly open. The electrician opened the door, grabbed Employee #1, walked him out of the room, and sat him down in a chair in the hallway. The other electrician and apprentice working in the MRI room heard the screams of the apprentice through the conduit and came running to see what had happened. In addition, the lights and power to the building shut down until the backup generator started. Employee #1 was transported to the hospital emergency room; within an hour, he was admitted to the Bridgeport Burn Center.