Abstract: On March 8, 2018, Employee #1 was required to lower and raise actors onto stage while simultaneously operating a fogger to mask the actors entering and leaving the stage. Operation of the fogger involved purging CO2 into the facility basement. The basement measured 24 foot by 24 foot and had 9 foot by 6 inch high ceilings. the basement was unventilated and had no alarms or monitoring equipment to test for carbon dioxide or oxygen levels. As Employee #1 was purging the line of the fogger, so that he would have cold carbon dioxide in the system, he collapsed. Six employees attempted to go down into the basement to rescue Employee #1 and turn off the carbon dioxide, resulting in all the employees being exposed to an oxygen deficient atmosphere. The CO2 was left venting for approximately 7 to 8 minutes before being shut off by one of the employees. Employee #1 was killed and two others were hospitalized and released the same day.