Ted Koppel on America's Vulnerable Power Grid in 'Lights Out':

Months or years of uninterrupted blackouts. A rising death toll from disease and societal chaos. And all because of a preventable vulnerability.

The new book "Lights Out: A Cyberattack, A Nation Unprepared, Surviving the Aftermath" looks at the risk of cyberattack facing the power grid in the United States and the inadequate measures being taken to protect it, despite clear warnings from an array of experts.

"Lights Out" is the new book from veteran journalist Ted Koppel, most widely known as the anchor and managing editor of "Nightline" on ABC from 1980 until 2005.

"It's not me giving this as a figment of my imagination," Koppel said on "Chicago Tonight." "Back in 2010, 10 former senior top officials–two former directors of the CIA, two former secretaries of defense, two former national security advisers–wrote a letter to a congressional committee. It was a secret letter, which spelled out their findings after dealing with the best experts they could find within the government. They came to the conclusion that tens of millions of people, in the wake of a cyberattack on one of the grids, could be without power for a period up to two years."

"The likelihood is great," Koppel added. "The current director of the NSA, Admiral Mike Rogers, said only a couple of weeks ago it is inevitable that one of our enemies will launch an attack like this, a cyberattack, on our infrastructure. The current commander of CENTCOM, General Lloyd Austin, told me it's not a question of if, it's only a question of when."