JUDY WOODRUFF:

Now a previously untold story of the Iraq war.

American soldiers on the ground were tasked with destroying thousands of rockets and artillery shells left behind by Saddam Hussein's regime. Some of those weapons contained chemical or nerve agents like mustard gas, remnants of the Iran-Iraq War of the 1980s.

That wasn't known, however, to the American troops who were assigned to destroy them. The New York Times has now published an investigation into the chemical weapons and the injuries sustained by some of those soldiers, which had not been publicly known.

We start with an excerpt of a short documentary The Times produced. In it, we see the destruction of mustard gas shells. We hear from some of the soldiers wounded by exposure.