Researchers who launched an experimental cyber attack on an electrical power plant caused a generator to self-destruct, alarming the federal government and electrical industry about what might happen if such an attack were carried out on a larger scale.

Economist Scott Borg projects that if a third of the country lost power for three months, the economic price tag would be $700 billion.

Computer experts have long warned of the vulnerability of cyber attacks, and many say the government is not devoting enough money or attention to the matter.