The leader behind the creation of the USS Indianapolis National Memorial died Thursday.

Dr. Giles “Gil” McCoy, 83, founder of the USS Indianapolis Survivors Organization, died of complications from cancer. He lived in Palm Coast, Fla.

McCoy served as a Marine aboard the legendary cruiser in 1945 when Japanese torpedoes struck, sinking the ship in 12 minutes.

About 900 men were thrown into shark-infested waters. Rescuers arrived several days later. Only 317 survived.

Wanting to remember both the survivors and the men lost that day, McCoy founded the survivors organization in 1960 and started working on the construction of a memorial.

After a 30-year battle, that memorial was built on the east bank of the Downtown Canal and dedicated in 1995.

Pat Finneran, who served as secretary for the memorial project, said McCoy was the man “who made it all possible.”

“Not many men . . . can say they had a hand in building a national memorial,” Finneran said.

Especially since organizing the USS Indianapolis survivors wasn’t always easy.

“At times it was like trying to herd cats in a room full of rocking chairs,” Finneran said.

But Mary O’Donnell, whose husband, Jim, was aboard the USS Indianapolis, said the pain of getting the monument built was worth it for McCoy.

“It was always his dream that we have that,” O’Donnell said.