Son drowns while scattering father's ashes: 'Honoring your last wishes, daddy'

(INSIDE EDITION) A grieving son drowned while spreading his father's ashes over the cold waters of Lake Superior, his family said.

Robert Louis, 59, and six relatives had set sail on a 19-foot wooden boat in Michigan's Upper Peninsula to fulfill the last request of his father, who died two weeks ago after battling Alzheimer's for several years.

All seven had been plunged into the lake after their boat made a sharp turn, witnesses said, according to authorities. People on board a passing pontoon craft pulled six members of the party from the water.

But Robert was nowhere to be found.

Divers found his body Monday, one day later. "He tried to grab the boat as it was circling around him ... and the prop hit him. I'm not sure if it made it so he couldn't swim or if it injured him enough to be life-threatening," Alger County Sheriff's Department Officer A.J. Schirschmidt told WLUC-TV.

Robert had dedicated his life to caring for his ailing father, whose health severely declined as he suffered the debilitating effects of Alzheimer's.

"Just everybody was his friend, he was very helpful, kind," his brother, Joe, told the station. "The kind of guy that would run into a building on fire to help."

He was also known for his guitar playing and love of music. He often picked up his instrument and led friends and neighbors in song.

Lifelong friend Tom Reed described him as "an unstoppable. Loving, caring soul that poured his heart out to everyone he met," on a GoFundMe page established to help with Robert's funeral costs.

He "had a cheerful voice and a laugh you will never forget," Reed said.

A few days ago, Robert posted on his Facebook page that he was in northern Michigan with his family, preparing for Sunday's journey to spread his father's ashes over Lake Ontario.

"I am honoring your last wishes, daddy," Robert wrote.