UNITED STATES
DEPARTMENT OF LABOR

At approximately 12:50 p.m. on May 16, 2003, Employees #1 and #2 were working as Troublemen for an electrical power utility company. They were troubleshooting a fault in an underground 16,340 volt power distribution system. Employee #2 had rigged a remote switching pulley system in order to operate the switch from outside of the vault. The switch was a 1964 ESCO manually operated oil switch, Serial Number 64073. The switch had been installed in June 1974. When the switch was thrown, Employees #1 and #2 heard and felt an underground electrical concussion. Both employees went to the vault manhole to look inside to see if they could determine where the fault had occurred. While they were standing at the manhole, approximately three to four minutes after the switch was thrown, it exploded. Flames came out of the vault manhole and from the perimeter of the vault cover. Employee #1 suffered second and third degree burns to the hands, ears, face, top of head, and left eye. He had been wearing a Nomex jump suit, two long sleeve undershirts, Levis, and work boots. He had no eye or hand protection and no hard hat. Employee #2 suffered second and third degree burns to the left side of the face and tinnitus in his left ear. He had been wearing a Nomex jump suit, two tee shirts, leather gloves, dark glasses (not ANSI Z87), work boots, and jeans. He did not have a hard hat. Both employees were hospitalized for treatment of their injuries.