Abstract: Employee #1 was standing in a 49 in. deep by 6 to 7 ft wide excavation. A 48 in. deep by 3 ft wide trench was being dug, extending out from the excavation, and Employee #1 was about 7 to 8 ft from an oil well flowline that ran diagonally across the new trench. Employee #2, who was operating a Case 580E backhoe, was attempting to remove a 10 in. by 18 in. rock that weighed between 20 and 30 lb from the vicinity of the flowline. Either falling rocks or the backhoe bucket ruptured the Centron fiberglass epoxy line pipe, CEN-450, and mixed crude oil/sour gas (87,000 PPM hydrogen sulfide) under 80 psi spewed out, striking Employee #1. Instead of climbing out of the trench in an upwind direction, he ran downwind to the excavation and collapsed. Employee #2 attempted to rescue him without wearing SCBA. When he realized that he was being overcome, he managed to exit the ditch and ran upwind before fainting. Employee #2 recovered without assistance, but Employee #1 could not be revived. In an oil field, employees should not be in a trench or excavation while a backhoe is being operated. They should be upwind and out of range of the boom to avoid danger from ruptured lines.