'Plot Would Have Killed Thousands'

Aug. 6, 2007 — -- Terrorists who had planned to detonate gel-based explosives on U.S.-bound flights from London last August would have achieved mass devastation, according to new information from Homeland Security Secretary Michael Chertoff in an exclusive interview with ABC News.

"I think that the plot, in terms of its intent, was looking at devastation on a scale that would have rivaled 9/11," Chertoff told ABC's Pierre Thomas. "If they had succeeded in bringing liquid explosives on seven or eight aircraft, there could have been thousands of lives lost and an enormous economic impact with devastating consequences for international air travel."

Sources tell ABC News that after studying the plot, government officials have concluded that without the tip to British authorities, the suspects could have likely smuggled the bomb components onboard using sports drinks.

The components of that explosives mixture can be bought at any drugstore or supermarket; however, there is some question whether the potential terrorists would have had the skill to properly mix and detonate their explosive cocktails in-flight.

But they can work — scientists at Sandia National Laboratory conducted a test using the formula, and when a small amount of liquid in a container was hit with a tiny burst of electrical current, a large explosion followed. (Click on the video player on the right side of this page to view the video.)

The test results were reviewed today by ABC terrorism consultant Richard Clarke, who said that while frequent travelers are upset by the current limits on liquids in carry-on baggage, "when they see this film, they ought to know it's worth going through those problems."

One official who briefed ABC News said explosives and security experts who examined the plot were "stunned at the extent that the suspects had gamed the system to exploit its weaknesses."

"There's no question that they had given a lot of thought to how they might smuggle containers with liquid explosives onto airplanes," Chertoff said. "Without getting into things that are still classified, they obviously paid attention to the ways in which they thought they might be able to disguise these explosives as very innocent types of everyday articles."

Chertoff speaks candidly about those moments when Homeland Security learned about the potential attack, and the terrorists had not yet been captured.

"This was very, very tightly held, because the British were concerned about any possibility of a leak getting out. Obviously, the intelligence folks knew, the senior intelligence folks, the president, senior leaders in the White House," he said. "Within my own department, only the deputy and I were initially told about this."