Abstract: At 3:45 p.m. on January 4, 2017, three employees were performing maintenance duties for a public transportation railway. Employee #1, a track worker, a Track Supervisor and a Lead Track worker, all on the Emergency Response Team, were instructed to make an emergency repair. The maintenance was to take place in a tunnel with a radius of 8-feet-4-inches and a diameter of 16-feet-8-inches. The portion of track being worked on measured 14-feet-wide by 200-feet-long. The task required the Employee #1 to enter the track bed and secure the loose and broken fasteners that hold the running rails together. The running rails are located 4-feet-8 1/4-inches apart. In order to make the repair, a gauge rod measuring 6 feet, and a track wrench were used to secure the fasteners. During this maintenance operation, the possibility of unintentional contact with the 3rd rail is present. The third rail was energized at 750-volts at the time of the incident. There is a cover board located above and behind the third rail which acts as a guard. However, the third rail is unguarded on the trackside, where the employees were working. The third rail is located approximately 7-inches above the ground on average. The track side of the third rail is located 2 feet from the running rail and the center of the third rail is positioned approximately 26 inches from the running rail. During the time of the incident, the victim worked within 3-feet-9-inches of the energized third rail. Employee and employer interviews determined that Employee #1 attempted to install the gauge rod over top of the running rails instead of installing it underneath of the running rails because it makes contact with the third rail virtually impossible. Employee #1 stated that "I had a gauge rod in place with my left hand and had to use a track wrench with right hand to tighten the rod. Next thing was an explosion. I saw yellow, red, and white bursts of light and then only tunnel out of my right eye. I fell back after the explosion." The employee contacted the third rail with the gauge rod causing the explosion. As a result of the accident, Employee #1 experienced burns on his left side, nerve damage, headaches, and a myriad of psychological issues.