The plane went down at about 3pm Saturday afternoon.
Search crews found what was left of a 1975 Piper single-engine plane.
The bodies of the pilot and another man were recovered from the water.
The pilot was identified as William Gensler, a flight instructor from Racine.
The Coast Guard says the plane could hold four people, so they are continuing to search for more victims.
The plane was en route from Racine to Oshkosh, Wisconsin.