Stanley Rehm, Gary's oldest uncle on his father's side, said his nephew helped save up to 20 lives following the collision

One of the seven sailors killed in the crash between a U.S. Navy warship and a shipping vessel was trapped below decks and drowned after he heroically dived into a flooded compartment to save his shipmates, his uncle said.

The USS Fitzgerald was taking on water and officers ordered the bulkheads closed while Fire Controlman 1st Class Gary Leo Rehm Jr., was still under water, Stanley Rehm told WKYC.

The U.S. Navy has declined to comment on Stanley Rehm’s version of events, though the story of Gary Rehm’s heroism is being widely circulated among sailors, PEOPLE can confirm.

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Credit: U.S. Navy/AP

Rehm, 37, from Elyria, Ohio, joined the Navy in 1998 fresh out of high school. He was just three months from retiring with full benefits – following in the footsteps of his grandfather, who served in the Navy in World War II.

Rehm saved up to 20 lives by going into dangerous parts of the ship that had been breached in the collision and helping his fellow sailors get to safety, his uncle said.

“He went back to get the other ones and I guess from what I understand they had to close the hatch, because the ship was taking on water,” Stanley Rehm told WKYC. “He died a hero trying to save the people on his ship.”

Credit: Iori Sagisawa/Kyodo News/AP

Because he was older than most of his fellow shipmates, Stanley told The Daily Beast that Gary, 37, called them his “kids.”

“He said, ‘If my kids die, I’m going to die,’ ” the uncle said, adding, “He could have walked away and been safe.”

“He always helped everybody,” Stanley told WKYC. “Somebody needed a helping hand, he was there to help them. He was just that kind of guy.”

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According to WKYC, Gary was married but had no children. His family said he will be buried at Arlington National Cemetery.

In the wee hours of Saturday morning, the Philippine container ship ACX Crystal smashed into the much smaller Arleigh Burke-class destroyer off the coast of Japan. The brunt of the collision came in the sleeping berths were much of the crew was asleep.

Also killed were Ngoc Truong Huynh, 25, Dakota Kyle Rigsby, 19, Alexander Douglass, 25, Noe Hernandez, 26, Victor Ganzon Sibayan, 23, and Xavier Alec Martin, 24.