DULUTH, Minn. -- A Minnesota man was killed when the small aircraft he was piloting crashed on the ice of a harbor, authorities say.

The plane went down Friday afternoon near the Richard I. Bong Memorial Bridge, which crosses the Saint Louis Bay, connecting Duluth, Minnesota, and Superior, Wisconsin.

The victim, identified only as a 52-year-old Hermantown man, was the only person aboard, the St. Louis County Sheriff's Office said in a news release. The release said that no structures in the area were damaged.

Sheriff Gordon Ramsay described the plane as a smaller model in a tweet and said it was partially submerged when crews first arrived to search for potential survivors.

The Federal Aviation Administration and the National Transportation Safety Board are investigating.