By any standard, last week was a downbeat week for U.S. Navy news. First the Navy staff released its long-awaited report chronicling the fire that immolated a major amphibious warship, USS Bonhomme Richard, at its moorings in San Diego a year ago. Naval magnates declared the ship a total loss. Unsurprisingly, then, the rapporteur, Vice Adm. Scott D. Conn, is unsparing in his judgments. He finds fault not just with the ship’s crew but with senior officers throughout the U.S. Pacific Fleet hierarchy.Consequences will doubtless follow. The money quote from the Bonhomme Richard report, though, comes from the vice chief of naval operations, Adm. Bill Lescher, who endorsed its findings: “The loss of this ship was completely preventable.” That seems fair. …