KENT, Wash. -- At 33, Daniel Diaz had three children of his own, but it was someone else's son he died saving.

Diaz and his family headed out to the Columbia River near Hood River, Oregon to celebrate the Fourth of July. But what was supposed to be a pleasant outing suddenly took a grim turn.

From one bank, the group saw a little boy trying to swim across. But the water was the width of two football fields, family members said. And when the boy began struggling, Daniel Diaz jumped in to get him. Within minutes, the man found himself in trouble.

"I guess he got tired; I don't know exactly what happened," said his wife, Fara Diaz.

Fara Diaz said her husband had undiagnosed circulatory problems. She can only assume that her husband went into cardiac arrest as he held the 12 year old above water, waiting for the rescue boat to arrive.

"Next thing I know, he was in trouble. He hollered my name and he went under," she said. "I was devastated. I was just totally devastated."

Family members say Daniel Diaz sacrificed his life for a 12-year-old boy whose name he didn't know. The Diaz family still hasn't learned the boy's name.

"I had several people come up to me during the recovery process, thanking me and saying what a hero he was," said Fara Diaz said. "I miss him a lot. I'm just grateful we had the opportunity to spend more time together."

To daughter Britney Diaz, her father still lives on.

"When you lose someone and you miss them, they're always here in your heart," she said.

Fara Diaz is waiting for the coroner's report, which she hopes will shed light on her husband's sudden death. As a part of her healing process, she also hopes to connect with the 12-year-old boy her husband saved.