Abstract: On July 25, 2006, a heavy equipment operator was using a Link Belt 5800 track hoe excavator in a fly ash pit. He loaded trucks that hauled the fly ash to an on-site landfill at the Dayton Power and Light (DP&L) Stuart Station Plant in Aberdeen, Ohio. The pit (a former pond) had been dewatered, and digging activity had been ongoing for approximately three months. There were two excavators digging and loading trucks. The fly ash walls of the pit collapsed, engulfing his excavator up to, and around the cab. The cab was air-conditioned, and the material broke through the windows and trapped the operator in the cab. He attempted to climb out the roof hatch of the cab but was unsuccessful. The operator was extracted by DP&L emergency medical technicians, and transported to a hospital by the Brown County Life Squad. The employee later died in the hospital from asphyxia.