The soldiers at the blast crater sensed something was wrong.
It was August 2008 near Taji, Iraq. They had just exploded a stack of old Iraqi artillery shells buried beside a murky lake. The blast, part of an effort to destroy munitions that could be used in makeshift bombs, uncovered more shells.
Two technicians assigned to dispose of munitions stepped into the hole. Lake water seeped in. One of them, Specialist Andrew T. Goldman, noticed a pungent odor, something, he said, he had never smelled before.
He lifted a shell. Oily paste oozed from a crack. “That doesn’t look like pond water,” said his team leader, Staff Sgt. Eric J. Duling.