INDIANAPOLIS -- In April 1945, James Clark Davis wrote a letter to his mom while on the USS Indianapolis.
"Please don't worry about me," he wrote. "I'll probably be home when you least expect me."
Three months later he went missing when the cruiser was torpedoed by a Japanese submarine. Davis was never found.
Seventy-two years ago Sunday, the USS Indianapolis went down somewhere in the Philippine Sea.
In a series of letters, Davis described to his mother the excitement of being a naval radioman on one of Indianapolis' most famous namesakes during World War II.
"Sure am sorry I haven't written before now," Davis wrote in his first letter from boot camp. "Oh boy, have I gone threw the wringer. [sic]"
Davis told his mother about boot camp, proud of his high score on the Morse code tests -- sailor's language, as he called it.
"I don't mean swearing," he assured his mom.
But he was also proud of the USS Indianapolis, saying he was "very glad to be one of its crew."
To 19-year-old William Friend Emery, the USS Indianapolis was supposed to be safe. Emery's father, a lieutenant commander of the Navy, pulled some strings to get him on the cruiser, nicknamed at the time "Lucky Indy" for its relative safety throughout the war. At the time Emery was assigned to the USS Indianapolis, it hadn't sustained any damage from the enemy.
Emery soon sent his family a letter, asking them to send his "gal" a ring. Mere days later, Emery died in the attack, leaving his family to wonder what was going through his mind when he sent the letter.
Commissioned in 1932, the USS Indianapolis was home to Davis, Emery and 1,194 other people during World War II. The ship was involved in Pacific battles in New Guinea and Iwo Jima.
Perhaps the most famous part of the story of the USS Indianapolis was a secret mission to deliver parts of an atomic bomb that would be dropped on Hiroshima.
A crew member wrote the following note after dropping off the "mysterious cargo:"
"The secret cargo was placed in one of our hangar decks. A 24-hour marine guard with orders to shoot to kill anyone nosy enough to get near the hangar deck."
The ship went to Tinian Island at top speed, breaking speed records along the way, then dropped off the components.
"Little did we know what was in store for us," the crew member wrote.
Days later, the Indy was hit by two torpedoes fired by Japanese submarine I-58. One hit next to a fuel tank and powder magazine, causing an explosion that tore the ship apart. Lucky Indy sank in just 12 minutes. About 900 people made it into the water alive.
What happened next has been called the worst shark attack in U.S. history.
For days, the survivors swam in shark-infested waters, waiting on a rescue as sunburn and dehydration took their tolls. At first, the sharks attacked only the dead bodies, but they eventually started on the living.
One group of survivors opened a can of Spam, the primary ration at the time. When they opened it, a group of sharks gathered all around them.
On the fourth day in the water, a Navy plane flying overhead spotted the survivors and radioed for help. Another plane came and dropped rafts and supplies. Lt. R. Adrian Marks of Frankfort, Indiana, the pilot of the second plane, saw the sharks attacking the survivors and landed, disobeying direct orders. He saved 56 people with his actions.
''I met you 30 years ago,'' Marks said at a USS Indianapolis reunion in 1975. ''I met you on a sparkling, sun-swept afternoon of horror. I have known you through a balmy tropic night of fear. I will never forget you.''
It took one more day for all the survivors to be picked up by nearby ships. In all, 317 men survived, the same number as the area code of Indianapolis.
A Local Hero
Indianapolis' James O'Donnell, then 25, was asleep on the main deck of the ship when the torpedoes hit.
"You woke up and looked forward and all you could see was a big sheet of flame," O'Donnell said in an archive interview. "And the first torpedo took the bow off. The second hit a magazine and ruptured everything."
O'Donnell survived the torpedo, and the sinking, and the days in the water with the sharks. After time in the water, he said some people began to hallucinate.
"They'd say 'There's a ship over there,' and they'd swim away and you'd never see them again," he said. "'There's an island over there.' They'd swim away and you'd never see them again. 'I'm going down to the mess hall to get a drink. They'd dive underwater and swallow a bunch of saltwater. In about four hours, they're gone."
O'Donnell was the only man from Indianapolis to survive, and one of just 10 from Indiana. After he returned home, he joined the Indianapolis Fire Department. He retired as a lieutenant 35 years later.
O'Donnell died in 2013. There is a statue dedicated to him at City Market.
For O'Donnell's friends and family, as well as the living survivors of the USS Indianapolis, July 30 is a day for healing, for peace.