The Cessna crashed on Monday afternoon as the team left for a trip across the lake to deliver organs to a clinic at the University of Michigan in Ann Arbor.
Minutes into the 40-minute flight, the plane sent a distress signal. The cause of the crash was unknown, but it was raining lightly at the time of the accident.
The patient, who was to receive the transplant, was in critical condition, but privacy concerns kept doctors from revealing what sort of transplant was needed.
The water in Lake Michigan had a temperature of 14 degrees Celsius and those on board would not have been able to survive 15 hours in water of that temperature.