The Sinking of the USS Indianapolis Triggered the Worst Shark Attack in History

The USS Indianapolis had delivered the crucial components of the first operational atomic bomb to a naval base in the Pacific, racing from San Francisco to Tinian, one of the Northern Mariana Islands, in a record-breaking ten days.

In just under two weeks, the bomb would level the Japanese city of Hiroshima. But for now, on July 28, 1945, the Indianapolis was sailing from Guam, without an escort, to meet the USS Idaho in the Philippines’ Leyte Gulf, where the two warships would prepare for the Allied invasion of Japan.

July 29 was quiet, with the Indianapolis traveling through swells in the seemingly endless Pacific Ocean at a speed of about 17 knots. As the sun set, the sailors played cards and read books; some spoke with the ship’s priest, Father Thomas Conway.

Shortly after midnight on July 30, a Japanese torpedo hit the Indianapolis, ripping off its starboard bow and igniting a tank containing 3,500 gallons of aviation fuel into a pillar of fire. Then, another torpedo from the same submarine struck closer to midship, hitting fuel tanks and powder magazines and setting off a chain reaction of explosions that effectively ripped the Indianapolis in two.

Still traveling at 17 knots, the ship began taking on massive amounts of water; it sank in just 12 minutes. Of the 1,196 men aboard, about 900 made it into the water alive. Their ordeal was just beginning.

As the sun rose on July 30, the survivors bobbed in the water. Life rafts were scarce. The living searched for the dead and appropriated their life jackets for those who had none. Hoping to maintain some semblance of order, the sailors began forming groups—some small, some made up of several hundred men—in the open water. Soon enough, they would be staving off exposure, thirst and sharks.

“There was nothing I could do but give advice, bury the dead, save the life jackets and try to keep the men from drinking the salt water,” Lewis Haynes, the ship’s chief medical officer, later recalled. “The real young ones—you take away their hope, you take away their water and food—they would drink salt water and then would go fast. … They would get diarrhea, then get more dehydrated, then become very maniacal.”

Sharks were drawn in by the sound of the explosions, the sinking of the ship, and the thrashing and blood in the water. Though many shark species live in the open waters of the Pacific, few are as aggressive toward humans as the oceanic whitetip. Experts generally agree that the Indianapolis sailors fell victim to oceanic whitetip sharks and possibly tiger sharks in what is considered the worst shark attack in history.

“Every now and then, like lightning, [a shark] would come straight up and take a sailor and take him straight down,” survivor Loel Dean Cox told BBC News in 2013. “One came up and took the sailor next to me. It was just somebody screaming, yelling or getting bit.”

At first, the sharks focused on the floating dead. But the survivors’ struggles in the water attracted more of the animals, which could feel their motions through the lateral line, a series of receptors along a shark’s body that detect changes in pressure and movement from a distance.

USS Indianapolis Crew Battled Sharks and Hallucinations

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As the sharks turned their attention to the living, the survivors sought safety in numbers. They realized they had the best odds in a group, ideally toward its center. The men on the margins or, even worse, alone were the most susceptible to attacks. When someone died, the remaining sailors would push the body away, hoping to sacrifice the corpse in return for a reprieve from a shark’s jaw.

Many of the men were paralyzed by fear, unable to even eat or drink from the meager rations they had salvaged from their ship. One group of survivors made the mistake of opening a can of Spam—but before they could taste it, the scent of the meat drew a swarm of sharks around them. The sailors got rid of their meat rations rather than risk a second swarming.

As the days passed, the chances of rescue seemingly dimmed. Though Navy intelligence had intercepted a message from the Japanese submarine that torpedoed the Indianapolis, describing how it sank an American battleship along the vessel’s known route, officials disregarded the dispatch as a trick to lure rescue boats into an ambush.

Meanwhile, hundreds of survivors succumbed to heat and thirst or suffered hallucinations that compelled them to drink the seawater around them—a sentence of death by salt poisoning. Those who slaked their thirst would slip into a state of delirium, foaming at the mouth as their tongues and lips swelled. They often became as great a threat to the survivors as the sharks circling below; many dragged their comrades underwater with them as they died.

Around 11 a.m. on August 2, the survivors’ fourth day in the water, a Navy plane flying overhead happened to spot the stranded sailors. The pilot radioed for help, and within hours, a separate seaplane manned by Lieutenant Adrian Marks returned to the scene, where it dropped rafts and survival supplies. When Marks saw men being attacked by sharks, he disobeyed orders and landed in the infested waters, taxiing his plane to help the wounded and the stragglers, who were at the greatest risk.

A little after midnight on August 3, the USS Cecil J. Doyle arrived on the scene and pulled the last survivors out of the water. Of the Indianapolis’ original 1,196-man crew, only 316 remained. Estimates of the number who died from shark attacks range from a few dozen to more than 150. Though the specter of sharks looms large in the warship’s story, the majority of the sailors died of exposure, lack of food and water, injuries from the explosion, exhaustion, and other causes. Today, the Indianapolis’ sinking is remembered as one of the deadliest naval disasters in American history.

In the aftermath of the rescue, the Navy court-martialed the Indianapolis’ captain, Charles B. McVay III, for failing to save his ship. Officials were eager to place the blame on McVay instead of acknowledging the series of errors that led to both the wreck and the survivors’ ordeal. In addition to denying the Indianapolis an escort, the Navy failed to warn the captain that he was traveling directly into the path of an enemy submarine. When the Indianapolis didn’t show up at its intended destination, no one reported the ship missing. It was only by chance that a passing plane found the surviving sailors.

At McVay’s December 1945 trial, the Navy convicted the captain of “hazarding his ship by failing to zigzag,” a technique used to avoid torpedoes. The court arrived at this decision despite the testimony of a surprising witness: Mochitsura Hashimoto, the commander of the Japanese submarine that sank the Indianapolis. To prosecutors’ chagrin, Hashimoto said that zigzagging would have had little effect in preventing the attack.

McVay’s conviction effectively ended his Navy career, and he died by suicide in 1968, reportedly while holding a toy sailor gifted to him by his father in his hand. It was only in 2001 that the Navy exonerated McVay, adding a congressional resolution clearing the captain’s name to his official file.

As for the Indianapolis itself, a research vessel owned by Microsoft co-founder Paul Allen discovered the ship’s wreckage at the bottom of the Pacific Ocean in August 2017. The wreck site is now under the care of the Navy, which has left it undisturbed as a war grave for the hundreds of soldiers who died in the sinking.

“Even in the worst defeats and disasters, there is valor and sacrifice that deserves to never be forgotten,” wrote Sam Cox, director of the Naval History and Heritage Command, in a 2017 essay. “[They] can serve as inspiration to current and future sailors enduring situations of mortal peril. There are also lessons learned (and in the case of the Indianapolis, lessons relearned) that need to be preserved and passed on, so that the same mistakes can be prevented, and lives saved.”

Natasha Geiling | | READ MORE

Natasha Geiling is an online reporter for Smithsonian magazine.

Meilan Solly | | READ MORE

Meilan Solly is Smithsonian magazine's senior associate digital editor, history.