Fatal accident

Three employees were working on a leaking crude oil flow line that connected a production well to its tank battery. They dug a trench to access the leaking flow line and cut out a 6-ft. long section from the pipe using a cold cutter. Two of the employees attempted to thread the cut on the flow line with a manual pipe threading machine (threader) but the dies on the threader were dull. Therefore, the workers asked the office to have new dies for the machine delivered to the site. Instead of installing the new dies in the manual pipe threader that was used earlier, the dies were installed in an electric pipe threader. Two of the employees got in the trench with the electric pipe threader and started to thread the exposed pipe when flammable vapors were ignited by the electric pipe threader. As a result, a flash fire engulfed the trench in flames. The third employee discharged two fire extinguishers to extinguish the fire. The two employees that were in the trench were hospitalized with second and third-degree burns to their arms, neck and faces. One of these employees died at the hospital. The other burned employee was hospitalized and released at a later date.
SOURCE: OSHA