Enemy torpedoes slammed into the USS Indianapolis under darkness in the South Pacific, just after the U.S. Navy ship had delivered the enriched uranium and other critical components that would be used in the atomic bombs dropped on Japan.

Minnesotan Erwin Hensch, one of 1,200 or so sailors and Marines aboard, soon found himself flailing in the water among the fewer than 900 who initially survived the cruiser’s sinking.

Over the next five days, hundreds more would fall victim to the relentless attack of sharks and other peril.

“I was absolutely determined to make it because I had a brand new wife at home and I’d seen her only a few times since we were married,” Hensch told the Albuquerque Journal in 1969. “I didn’t give up.”

Hensch died Oct. 15 at a senior living facility in Crosby, Minn. The longtime Burnsville resident was 93 and had been battling complications brought on by Alzheimer’s disease.

The Indianapolis met its fate on July 30, 1945, four days after arriving from San Francisco at a U.S. base on Guam’s Tinian island with the secret cargo that would end World War II. The ship sank in just 12 minutes and the disaster remains the Navy’s greatest single loss of life at sea.

“Shark attacks began with the coming of daylight,” according to an exhaustive narrative written by Patrick J. Finneran, former executive director of the Indianapolis’ Survivors Memorial Organization. “One by one sharks began to pick off the men on the outer perimeter of the clustered groups. Agonizing screams filled the air day and night. Blood mixed with the fuel oil.”

“The survivors say the sharks were always there by the hundreds — swimming just below their dangling feet. It was a terror-filled ordeal — never knowing if you’d be the next victim.”

The ordeal left Hensch, the ship’s assistant chief engineer and a Navy lieutenant, 25 pounds lighter and ailing. After weeks in a Guam hospital, he went to Washington, D.C., and helped Capt. Charles McVay prepare hundreds of condolence letters for the families of those who perished.

Hensch also testified during McVay’s court-martial, a trial that “I was frankly angry about … because I thought McVay acted properly in all circumstances,” Hensch told the Journal. “He was a fine officer.”

With Hensch’s death, there are no longer alive any Minnesotans who were on the Indianapolis, according to Ed Harrell, a survivor who lives in Tennessee and tracks his shipmates. “Now there’s 37 of us,” said Harrell, referring to himself and the others still alive.

Sue Ecklund, a daughter of Hensch’s who lives in Burnsville, said her father spoke little about he war until after he retired, “then he started speaking about it a lot to us, his grandchildren and organizations.”

She said what “has stuck with me the whole time were not the gory details but my father’s faith in God. … He always seemed very calm and together about what happened.”

Hensch, who grew up on the family farm in Sanborn, Minn., returned to the University of Minnesota after the war and earned a master’s degree, then began his career as city manager in Fergus Falls, Minn. He moved to Duluth and was that city’s public works director for eight years, then took the same job in Albuquerque, N.M.

The Hensches, who were married on Christmas Day 1941, moved to Burnsville in 1980 upon Erwin’s retirement.

Along with Ecklund, Hensch is survived by his wife of 70 years, Helen, daughter Judith Trujillo, of Portland, Ore., and son Thomas of Minneapolis. A memorial service will be held at 2 p.m. Nov. 23 at Heartwood Living Community in Crosby.