Abstract: On May 5, 2018, Employee #1 was retrieving a plastic liner bag from a chemical container that had fallen into Reactor CP-2; a confined space. The permitting process, including air monitoring and setting up of ventilation, had not been conducted. As Employee #1 descended a ladder to access the reactor, he passed out at the first rung and fell to the bottom of the reactor. A coworker, who witnessed Employee#1 enter the space, contacted the control room to notify them of the incident. Emergency services were contacted and, upon arrival, recovered Employee #1 from the reactor. Employee #1 was determined dead. Air monitoring conducted by emergency services, following the incident, showed an oxygen concentration of eleven percent.