Abstract: At approximately 11:15 a.m. on October 26, 2000, two natural gas field pumper/operators were involved in a pipeline "pigging" operation. Their task was to remove a cupped pig from a pig receiver installation. The two men had isolated the receiver from all upstream and downstream pressure, however the original line pressure (680 pounds per square inch) was still stored in the receiver tube. The next step was to release this stored pressure to the atmosphere. Three valves were opened to accomplish this; a one-inch valve located nearest the main isolation valve, a 2-inch valve near the receiver door and a weep valve located right at the receiver door. The operators observed and heard the pressurized natural gas escape from these valves to the atmosphere. The surviving operator, Employee #1, stated that he also observed the indicator needle in the pressure-indicating gauge, located on the top of the receiver barrel, drop to zero. However, independent tests on the gauge showed that the gauge would not zero but instead read 20 pounds as its lowest reading. The operators then proceeded to open the receiver barrel door, a task that could not have been accomplished in the manner that it was accomplished had there still been pressure on the inside of the door. The pig was not located within easy reach as it always had been in the past. The operators reached inside the receiver but to no avail, it was not within reach. Employee #1 (the senior operator) told Employee #2 (an employee that had been on the job for three weeks) " Wait a minute I am going to get a mirror". Employee #1 proceeded to his truck toolbox for a mirror to use to reflect light into the receiver barrel to locate the pig. Employee # 1 stated that the next thing he heard was a loud pop, he looked up from the toolbox and could not see Employee #2 as the side of the truck was blocking his view of the ground. He walked around the truck and saw Employee #2 on the ground, severely injured. Employee #2 died at the scene.