OROFINO — A maintenance worker and Army veteran who was found dead at Dworshak Dam on June 30 died from work-related carbon monoxide poisoning, according to the Clearwater County Sheriff’s Office.

Eric Engle, an Army Corps of Engineers employee from Orofino, was operating a gas-powered pressure washer in a small access area leading to the dam’s diversion tunnel. The sheriff’s office said in a news release Tuesday that an autopsy and toxicology report revealed Engle succumbed to exhaust fumes from the pressure washer. He was 54.

The autopsy was ordered by the Clearwater County coroner.

Dylan Peters, a public affairs specialist at the Corps’ Walla Walla District, said the agency is conducting an internal safety investigation and is unable to comment on Engle’s death until it is completed. Peters was unwilling to say if any other agencies are investigating the workplace death.