Abstract: At 1:30 pm on October 17, 2019, an employee working for a meat processing plant was standing on the top of the tanker truck. The employee was using a tape measure gauging the depth of the waste blood product that was being pumped into the tanker for an adjacent rail tanker. A coworker found the employee lying on his stomach with his head and right arm inside the manhole of the tanker truck. The employee had lacerated his forehead but no other visible injuries were observed. The employee was unresponsive, was not breathing and had no pulse at the time. The employee was hospitalized which were attributed to unknown causes at the time the narrative was submitted. However, a measurement was taken with a four gas meter at the hatch opening shortly after the employee was discovered, which showed a hydrogen sulfide (H2S) level well above the ceiling level of 50 ppm.