RCMP say vandals used a shotgun and rifle to shoot out the insulator at a BC Hydro substation near Terrace.
Investigators say damage to the facility on the Thunder Bird Forest Service Road is estimated at over $10,000.
Police say the substation is also very important for the reliability of BC Hydro, Rio Tinto Alcan, and The Northwest Transmission Line, meaning additional losses will be felt when portions of the Alcan project at Kemano are shut down to make repairs.
RCMP Constable Angela Rabut says vandalism at the substation is an ongoing problem which has also impacted the environment.
Rabut says the damage was inflicted sometime in the past month or so.
Contact the Terrace RCMP detachment or Crime Stoppers with any information.