An explosive device exploded at a Nogales, Arizona power plant June 11, leading the FBI to open an investigation.
The incident occurred at the UniSource Energy Services Valencia Plant, according to The Arizona Republic. The explosion ruptured a diesel tank and caused a minor spill. The fuel did not ignite and the spill was confined to the immediate area, according to reports.
When local police received tips about suspicious activities, officials closed off the power plant and an adjacent car dealership. Since then, the FBI, the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Arizona Department of Public Services have investigated.
Officials said the reason for the thorough law enforcement response is the electrical substation in the area, according to reports.