Abstract: At 2:35 p.m. on November 2, 2019, an employee working as a journeyman lineman for a gas and electric company was working on the 100-foot steel transmission tower. The employer owns and operates the work site. The employee and Coworker #1 were replacing insulator string assemblies on lines where they are supported by the tower. The crew was using the employer's "Barehand Procedures" which allow performing the work with the transmission lines energized in accordance with a permanent variance from the Occupational Safety and Health Standards Board (OSHSB), State of California. The crew met at the employer's maintenance yard at about 5:00 a.m. and traveled to the site. They started work at about 8:00 a.m. after setting up their equipment and holding the required safety meetings. They had replaced 6 or 7 of 12 insulator strings. The crew was working on the center phase line on the southwest side. The employee and Coworker #1 were working on the hot end and two other coworkers were working on the cold end. The crew performed a visual inspection of the insulator string and all were satisfied that there was no evidence of damage therefore no further testing was required. When coworkers working on the cold end began to take up the strain using strain sticks to support the line, an arc flash causing an explosion. The employee sustained 2nd degree burns to his face, hands, chest and back and temporarily lost consciousness as a result. The employee was suspended by a personal fall arrest harness but did not fall, simply swinging away from the explosion. Coworker #1 and other coworkers were not injured. The coworker called the helicopter to return to the tower and pick him up and move him to the employee. The coworker connected the employee to the helicopter line which flew him to the landing zone while coworkers on the ground called 911. The employee and coworker were taken to the hospital for evaluation, where the employee was hospitalized due to electrical burns.