An EMP attack using a nuclear warhead detonated high above the Earth could damage electrical infrastructure across wide areas. Such an attack was first observed when a nuclear test in the South Pacific damaged streetlights in Hawaii over 1,300 km away. While terrorists could potentially launch an EMP attack against the US using a missile, accurately weaponizing a small nuclear bomb and achieving sufficient range would be very difficult. The nation's power grid is also vulnerable to cyber attacks, as evidenced by the Stuxnet virus damaging Iran's nuclear facilities despite being disconnected from the internet. Various solar, cyber, and infrastructure threats could potentially disrupt electricity availability.