Jim Kowalski, founder of Kowalski's Markets, has died in an accident involving a small plane in Canada on Thursday morning. While at first reports claimed he died from a plane crash, those theories are now being debunked.

Family member Deb Kowalski said Jim suffered a head injury in the unspecified incident in Red Lake, Ontario, and an autopsy is being performed, CBS Local reports. She said he was with a friend on a fishing trip.

"It was not a crash... and we don't exactly know how it happened," she explained, according to The Inquisitr, but did not elaborate.

Kowalski told TwinCities.com that Jim, 67, was with a pilot friend on a Canadian fishing trip, and that the other man "heard a noise, and [Jim] was gone."

The VP of Kowalski's Market also stated that he thinks a plane accident caused Kowalski a fatal head injury, but the mystery death wound was sustained while the private plane was still on the ground, rather than a crash, The Examiner reports.

According to MyFox9.com, Friday morning, Ontario Provincial Police confirmed Kowalski had been standing on the plane's floats as the it approached the shoreline. When the plane hit shore, he lost his balance and fell into the propeller, suffering a fatal injury.

The cause of death has still not been officially confirmed, and the investigations are still ongoing, The Christian Post notes.

Jim Kowalski founded Kowalski's Markets back in 1983. He and his wife, Mary Anne, co-owned what is now nine stores that employ nearly 1,200 people, CBS Local reports.

According to the company website, Jim and Mary Anne Kowalski have both received the highest honors in the industry; Jim as Minnesota Grocer of the Year and Mary Anne as the National Grocers Association Woman of the Year.

St. Paul mayor Chris Coleman shared his condolences, according to CBS Local.

"Jim left a lasting legacy in St. Paul and across the metro area. His passing is tragic and my heart goes out to his family," Coleman said.