With his 2-year-old son, Lucas, face down in the water, Miles Xiong didn't hesitate.

Not stopping to don a life jacket, the 35-year-old Shoreview man dove from a pontoon boat into Turtle Lake in Shoreview, where the family had been tubing Friday evening. With his pregnant wife, Laurie, and 7-year-old son, Noah, also in the water, he struggled to get the toddler and everyone else back to the boat. One by one, they clambered back aboard the craft -- but suddenly Xiong was gone, family members and friends said Saturday afternoon.

Laurie screamed for help. Then nearby boaters and authorities began a frantic search. But Xiong never reemerged. Rescue workers found his body more than an hour later in about 8 feet of water. He died late Friday night at Regions Hospital in St. Paul.

Ramsey County authorities said they aren't sure how Xiong drowned.

An autopsy was performed Saturday and results are expected in a few days, said Cmdr. Rolland Martinez of the Ramsey County Sheriff's Office. Alcohol was not a factor in the drowning, Martinez said.

"Any person who has kids would not think about putting on a life jacket [before] going in after their kids," said John Kim, Xiong's brother-in-law. "I would do the same thing."

Xiong's selflessness to save his family surprised no one gathered at his Shoreview home Saturday afternoon.

Kim's eyes teared up as he reflected on what he will miss most about Xiong: his cooking, his barbecues, his company, his generosity.

Xiong, a dental hygienist in south Minneapolis and a University of Wisconsin-River Falls graduate, was born in Laos, but emigrated to the United States after spending time in a refugee camp.

He met his wife in college and they eventually designed a home on the same property in Shoreview where she had lived as a child.

Laurie's mother, Jan Heaberlin, still lives nearby. She went down to the private launching area near her home after she heard about the accident to comfort her daughter and her children. All were cold and wet, she said.

Heaberlin said that Xiong's eldest son, Noah, may understand what happened to his father but that the younger children, including 4-year-old Tyler, can't quite grasp Friday's accident.

"I don't think the boys really realize," she said. "Kids that age don't know this is forever."

Kim also ran down to the beach. Laurie told him that she had made a quick decision to join her husband and Noah in the water to help Lucas, who was wearing a life jacket.

Family members said Xiong was a good swimmer.

As Kim sat with his sister on the shore Friday night, he said, he caught a glimpse of rescuers loading Xiong's body into an ambulance. "I just lost it," Kim said.

And now family members have to think about how they'll help Laurie, a physical therapist, raise her sons and get through another pregnancy safely. Tina Sivilay, a family friend, said she'll leave her Carver County home and move in with the family to make sure Laurie takes care of herself; the new baby boy is due in late July.

Both Kim and Sivilay described Xiong as a jack of all trades. He planted the lilies and geraniums that surround his home. And both of them said he was a role model for other husbands. When the guys would play golf, Xiong preferred to stay home and spend time with his family.