Abstract: On March 13, 2006, Employee #1 was working at a construction site in Alaska. Work was just starting for the season. Machinery needed to be started and moved after sitting in storage for about six months. The worksite was about a mile from the equipment yard, on the other side of a lagoon located near the airport. Employee #1 was attempting to drive a Hitachi 800 excavator to the work site to join two dozers that had already been moved there. Rather than take the road that had been used by the dozers, he elected to drive along the shore of the lagoon. About 500 feet after Employee #1 set out along the shore line, the excavator's left track fell through the ice, submerging the operator's cab and trapping Employee #1 under the ice. His body was recovered by divers two days later. An investigation revealed that ice on the lagoon was normally 5 to 6 feet thick at that time of the year, and that the water depth along the shore was 4 to 6 feet. In one area along the shore, however, a deeper spot had been dredged in the 1980s to a depth of about 20 feet. A sewage lagoon was located across the road from the dredged area, and a pipe had been buried under the road. It is speculated that the discharge from the pipe warmed the water in that area and prevented the ice from becoming thick enough to support the 165,000-lb machine.