Abstract: At 6:00 a.m. on May 3, 2019, an employee and three coworkers were breaking off a joint to run a clean up cycle on a drilling rig. The employee took over the controls and proceeded to lift the joint while the coworkers, two from night shift and one from day shift, wrapped and held tar paper around the joint in case any residual mud spilled out. As the joint was being lifted there was an audible pop, at which time the employee realized neither he nor the other driller had turned the mud pump off. Mud shot out of the pump with enough force to knock the employee and his coworkers backwards against equipment and guardrails, blowing off their hard hats and safety glasses and exposing them to the oil based mud. The mud injured the employee's eyes requiring hospitalization.