Why did U.S. soldiers detonate one of their helicopters before allegedly extracting Osama bin Laden's body from Abottabad, Pakistan?

Turns out, according to an ABC News report, it's because they were using a never before seen weapon of war, produced by a weapons research program that was only ever rumored to exist.

And now, the term "stealth helicopter" is born.

ABC News investigative reporter Brian Ross reports.

This video is from ABC News, broadcast Wednesday, May 4, 2011.