A 42-year-old Sherwood man died after his all-terrain vehicle fell into open water on Lake Winnebago.
The Milwaukee Journal Sentinel reported the man spent about an hour under water.
The Calumet County Sheriff's Department said the man was traveling across the ice at High Cliff State Park Marina on Saturday with a companion who was on another machine.
The pair came to some open water. The person on the first ATV crossed the water, but the man on the second machine did not.
His name was not immediately released.