Abstract: At approximately 11:00 a.m. on July 24, 2012, Employee #1, #2, #3 and #4, a crew, were conducting swabbing operations on an oil well site. The swabbing operation involved the removal of diesel fuel, crude oil and water from another well. A tank had been delivered from another site, which a swabbing operation was conducted. The tank was a metal vessel that was approximately 17 ft high by 12 ft in diameter. For the swabbing operation on this site, the crew filled the tank with salt water in preparation of a fracking operation. The crew noted that a leak was present on the bottom of the tank and proceeded to drain the tank to repair the leak. A welder proceeded to repair the bottom side of the metal tank. The tank was sitting on an angle on the back of a delivery flatbed truck. Employee #2, a welder, had finished welding work on the swabbing tank when all of the employees allegedly heard a hissing noise from the tank. After hearing the hissing noise, the crew walked away from the tank. An explosion occurred a few seconds later, which enveloped four of the employees standing to the south of the tank. The flash fire ignited the tank wheels on fire, but quickly burned out. Employee #1 received second and third-degree burns to the arm and head. Employee #2 received second and third-degree burns to 95 percent of the body, and later died due to injuries received. Employee #3 received second and third-degree burns to the arms and face. Employee #4 received burns to the arms. Employee #1, #3 and #4 were transported to the medical center burn unit, where they underwent burn treatment and were then hospitalized.