Abstract: Some employees were installing a new air conditioning system in a residence. A helper was working in an attic space, pulling a section of pipe through an opening in the west side of the space as another employee pushed the pipe. The employees below heard a bump and a scream, so one of them ran up to the attic. He called the helper's name but, getting no response, called for another employee to assist him. The two coworkers found the helper lying face down on the attic floor, with his head to the east. One of the coworkers tried to revive the injured employee while the other called for help. The helper was lying next to an electric water heater. Numerous electric conductors ran throughout the attic, and several junction boxes did not have covers. Additionally, grounding had not been provided for some of the wiring in the attic. The helper had been electrocuted, apparently when he contacted an energized part and a grounded surface at the same time.