Abstract: At approximately 12:00 a.m. on April 26, 2012, Employee #1 was working on an engine. Third party contractors were performing testing on a carbon dioxide activated system. As Employee #1 worked on the engine, carbon dioxide was being produced. The alarm on the carbon dioxide activated system did not sound. Employee #1, # 2, #3, #4, #5, and #6 were exposed to carbon dioxide poisoning. Employee #1 was transported to a medical center, where he received treatment for carbon dioxide inhalation and was then hospitalized. Employee # 2, #3, #4, and #5 were also hospitalized. Employee # 6 and #7 were treated at the hospital and released.