Abstract: Employee #1 and coworkers were engaged in a hot tie-in on a 2-in.-diameter plastic gas line that was pressurized to 50 psi. This involved connecting two pressurized lines by placing a clamp on the plastic line to crimp it and stop the gas flow, and then cutting the line downstream from the clamp. After the cap was cut off one end of the line, gas began to flow from the pipe. Employee #1 tried to tighten the clamp, but may have loosened it instead. The escaping gas exploded, probably ignited by a generator that was on a service truck parked about 15 ft away. Employee #1 was engulfed in flames and sustained burns that required hospitalization.