Decades of consolidation have left the Pentagon vulnerable to mishaps—including when the sole maker of a crucial type of gunpowder went offlineMINDEN, La.—Nearly two years ago, an errant spark inside a mill caused an explosion so big it destroyed all the building’s equipment and blew a corrugated fiberglass wall 100 feet. It also shut down the sole domestic source of an explosive the Department of Defense relies on to produce bullets, mortar shells, artillery rounds and Tomahawk missiles. The ramshackle facility makes the original form of gunpowder, known today as black powder, a highly combustible material with hundreds of military...
