Abstract: On December 5, 2008, Employee #1 was dispatched to the site to perform normal maintenance on the building's boiler equipment. Two domestic heating boilers and three comfort heating boilers were located in the room. Employee #1 was working alone in the room. An employee of a cleaning service entered the boiler room at approximately 10:00 a.m. to get a ladder and observed that Employee #1 was sweating profusely and the room was extremely warm. At 11:00 a.m. an employee of the building management company tried to reach the victim by phone and did not receive a response. Between 11:30 a.m. and 12:00 p.m. on December 5, 2008, the victim's supervisor arrived at the site (also, after trying to reach him by phone) and found the door to the boiler room locked. At approximately 12:00 p.m. Employee #1 was found unresponsive in a boiler room of a condominium complex. Employee #1's supervisor reported that one of the three comfort heating boilers was operating. When the supervisor obtained the key to the room, he found Employee #1 sitting on the floor leaning against a box unconscious. Employee #1 was pronounced dead at 12:25 p.m. at the scene. The medical examiner called the fire department and requested that carbon monoxide measurements be taken in the boiler room. The fire department measured approximately 1,400 parts-per-million of carbon monoxide in the room. Exhaust dampers on two of the comfort heating boilers were observed by the contractor to be partially closed during troubleshooting following the accident. This included the damper on the boiler that was operating when Employee #1's supervisor entered the boiler room. Following an autopsy, the medical examiner declared Employee #1 died of carbon monoxide intoxication.