A 1915 photograph of an artist’s depiction of the torpedoing of the Lusitania. The luxury liner, carrying 1,959 passengers and crew, was sunk by a German U-boat. (Library of Congress/ Prints and Photographs Division)

Daniel Stashower is the author of the Edgar-winning “The Hour of Peril: The Secret Plot to Murder Lincoln Before the Civil War.”

The Last Crossing of the Lusitania

By Erik Larson

Crown. 430 pp. $28

‘I’d never seen a more uneventful or stupid voyage,” declared one passenger on the Lusitania’s final crossing, but surely this was a minority opinion. On May 1, 1915, this “floating village in steel,” the jewel of Britain’s Cunard line, set forth from New York bound for Liverpool, carrying 1,959 passengers and crew members — including 189 Americans. German U-boats were patrolling the North Atlantic, and Germany had issued a grim warning: British shipping lanes were now a “zone of war,” and vessels flying the flag of Britain would be “liable to destruction.” To some, at a time when the entire world was waiting to see if America would be drawn into the war in Europe, the Lusitania appeared to be tempting fate. “The blowing up of a liner with American passengers may be the prelude,” wrote U.S. Ambassador Walter Page from London. “I almost expect such a thing.”

In contrast to Erik Larson’s previous blockbusters “The Devil in the White City” and “In the Garden of Beasts,” the broad strokes of this story will be familiar to most readers. But this enthralling and richly detailed account demonstrates that there was far more going on beneath the surface than is generally known. Though many believed that civilian ships would be safe from attack, codebreakers in London were tracking the movements of German submarines with the aid of a dead signalman’s codebook and were aware that the German navy considered the Lusitania to be “fair game.” Even so, few measures were taken to ensure the ship’s safe passage, raising troubling questions about the motivations of the British Admiralty.

‘Dead Wake: The Last Crossing of the Lusitania’ by Erik Larson (Crown)

William Thomas Turner, the Lusitania’s rugged and experienced captain, was not made aware of the codebreakers’ efforts, but he did receive assurances that the Royal Navy would provide an escort through British waters. When that escort failed to appear, Turner seemed unfazed. Outwardly, at least, the captain appeared to share the sanguine views of his employers. “The truth is that the Lusitania is the safest boat on the sea,” Cunard officials claimed. “She is too fast for any submarine. No German war vessel can get her or near her.”

As Larson demonstrates, however, the world had been slow to grasp the dark implications of the Unterseeboot, or U-boat. Some of the book’s most gripping chapters track the evolution of the submarine from “a suicidal novelty” to a brutally effective killing machine, together with the extraordinary burdens placed on the shoulders of the U-boat captains: “He alone determined when and whether to attack, when to ascend or dive, and when to return to base.” The captain alone bore the responsibility for all that occurred during a cruise, and not all of Germany’s leaders were comfortable with this. “Unhappily,” declared Chancellor Theobald von Bethmann Hollweg, “it depends upon the attitude of a single submarine commander whether America will or will not declare war.”

Thirty-two-year-old Walther Schwieger, in command of the U-20, “a pinpoint in a vast sea,” had acquired a reputation for ruthlessness after firing a torpedo at a presumably unarmed hospital ship. Nevertheless, crewmates insisted that he ran a “jolly boat,” and on one occasion, after sinking a freighter off the coast of Ireland, Schwieger even paused to rescue a struggling dachshund from the wreckage. By May 1915 he was regarded as one of Germany’s most knowledgeable commanders, and when rumors surfaced that Britain was about to launch an invasion, Schwieger was ordered to hunt and attack potential troop transports. Aboard the Lusitania, however, most passengers shrugged off the possibility of a torpedo attack. As one traveler noted, “The idea came to be regarded as a mild joke for lunch and dinner tables.”

Larson uses letters, journals and the accounts of survivors to reconstruct the shipboard experiences, and these are among the most vivid and often heartbreaking passages in the book. In one, Theodate Pope, one of America’s “few female architects of stature,” recalls the consternation of a fellow passenger who had been served a dish of ice cream but no spoon: “He looked ruefully at it and said he would hate to have a torpedo get him before he ate it.” In another, Nellie Huston, a 31-year-old traveling home to England, describes the unexpected challenges of trying to get into her top bunk in second class. “I don’t know if I was supposed to be able to spring right into it,” she explained in a letter home, “but I’m too heavy behind.” Charles Lauriat Jr., a noted Boston book dealer, came aboard with a priceless set of drawings by William Makepeace Thackeray and a one-of-a-kind edition of “A Christmas Carol” adorned with handwritten notations by Charles Dickens. Lauriat neglected to take out insurance, having judged that the risk “is practically nil.” In the end, he lost these literary treasures but managed to save a set of pictures of his baby. “They were my mascot,” he cabled to his wife.

These stories put a human face on the scenes of carnage when the Lusitania finally crosses the path of the U-20 on May 7, 1915. Lauriat’s experiences are especially harrowing, as he finds himself momentarily snagged in the ship’s wireless antenna and nearly dragged to the bottom. Pope was also among the survivors, but her traveling companions were not. She spent the rest of her life trying to contact them through spirit mediums. Huston did not live to mail the account of her struggles with the second-class bunk; her letter was found floating in her purse on the sea.

Turner appears to have been fully prepared to go down with the ship, but in the end his life jacket spared him as the Lusitania “seemed to be plucked from my feet by a giant hand.” The torpedo, as Larson explains, struck the hull at a particularly vulnerable spot, flooding the coal bunkers that ran the length of the ship and sending her to the bottom in just 18 minutes. As Schwieger himself noted, “She could not have steered a more perfect course if she had deliberately tried to give us a dead shot.” In the chaos, only six of the ship’s 22 conventional lifeboats were successfully launched.

“There can be no doubt that for many passengers death came suddenly and utterly by surprise,” Larson writes. “Passengers were crushed by descending boats. Swimmers were struck by chairs, boxes, potted plants, and other debris falling from the decks high above. And then there were those most ill-starred of passengers, who had put on their life preservers incorrectly and found themselves floating with their heads submerged, legs up, as in some devil’s comedy.” Of the 1,959 passengers and crew members, only 764 survived. Among the dead were 123 Americans. “We shall be at war with Germany within a month,” predicted one American official.

In fact, a further two years elapsed before America entered the conflict, and by that time a great many uncomfortable questions had surfaced about the Lusitania. Even Schwieger found it “inexplicable,” as he noted in the U-20’s log, that the ship had not been safely diverted to a more northerly route. Others wondered, in the face of Germany’s public warning and a well-documented surge of U-boat activity, why no military escort had been provided, though Turner himself doubted that it would have prevented the catastrophe. “It might,” he said, “but it is one of those things one never knows. The submarine would have probably torpedoed both of us.”

These questions are still being debated a century later. Larson’s account is the most lucid and suspenseful yet written, and he finds genuine emotional power in the unlucky confluences of forces, “large and achingly small,” that set the stage for the ship’s agonizing final moments. Turner, for his part, understood that some dangers were an unavoidable part of life at sea. Days before the Lusitania set off from New York, he testified at a hearing on behalf of families of passengers who perished aboard the Titanic three years earlier. Speaking to a panel of eight lawyers, the captain scoffed at the notion that a luxury ocean liner could ever be considered unsinkable. “Who told you that?” Turner snapped. When asked if he had drawn any lessons from the Titanic tragedy, he gave a chillingly blunt reply:

“Not the slightest,” he said. “It will happen again.”