Abstract: At 12:01 p.m. on November 24, 2020, an employee was working on the ceiling of a cleanroom that was not rated for working loads while troubleshooting an electrical issue with a Fan Filter Unit (FFU) HEPA filter. During this task, the employee fell approximately 12 feet through a ceiling panel to the cleanroom floor, which is as tough as concrete. The employee sustained a serious head injury, specifically a left frontal scalp hematoma with underlying fractures of both the anterior and posterior tables of the left frontal sinus. Preliminary investigation indicated that the employee may have contacted the edge of the entrance conveyor to Boost #2 prior to falling to the floor. The employee was hospitalized for treatment.