Abstract: At 1:15 p.m. on October 3, 2022, an employee and a coworker were performing repair work inside a sulfuric acid tank from a rolling scaffold near the center of the tank. Another coworker was performing safety attendant duties at the entry to the tank. All employees were wearing fall protection harnesses, hard hats, eye protection, ear protection, and gloves per the worksite's standard PPE requirements. The employees were working in a confined space and were implementing appropriate permit required activities. The confined space was well ventilated with forced air and the atmosphere within the tank was being monitored by the safety attendant. The employee was descending the scaffold when he fell approximately 20 feet to the bottom of the tank. The coworker in the tank heard a thud and looked down to see the employee laying at the base of the scaffold system. There were no issues with the set up of the rolling scaffold and the employee was not carrying anything at the time of his fall. The injuries suffered did not provide any evidence to support an attempt to break the employee's fall. This indicates the employee was most likely either unconscious or semi-conscious during the fall. The employee appears to have had a personal medical event while descending the scaffold. The employee suffered a head injury consistent with a fall onto a metal work surface from a height. The employee was admitted and treated at a local medical center, where he died on November 13, 2022.