An electrical worker was fatally injured at Lake Havasu City High school on Tuesday. Public safety officials responded at 12:17 p.m. to Lake Havasu High school in the 2200 block of Havasu Boulevard.

Police Sergeant Kirk Cesena said witnesses told officers they heard what sounded like a small explosion in a room where Andrew Hayes, 34, had been working to install temporary chillers to the building’s power supply.

Cesena said Hayes, of Lake Havasu, was not breathing and was unresponsive where located. He died following transport to Havasu Regional Medical Center.

The fire department said personnel from the Occupational Safety and Health Administration would be conducting a formal investigation of what was called an “industrial accident.”