The U.S. Coast Guard says a medical transport plane carrying five crashed into Lake Michigan and that one person has been rescued.
Petty Officer Nathaniel Parks said the plane went down shortly after 10 a.m. Friday a few kilometres offshore from Ludington, Mich.
A passenger was rescued shortly after noon.
Federal Aviation Administration spokeswoman Elizabeth Isham Cory said the Cessna 206 left Alma on Friday morning en route to Rochester, Minn. Alma is in central Michigan, about 240 kilometres northwest of Detroit.
Parks said a witness reported the crash and that the plane sent a distress signal via satellite.
A map of the plane's flight path from flightaware.com suggests problems developed early in the flight.
About one-third of the way into the flight, the westbound flight doubled back for a time over Lake Michigan and then turned straight north. It nearly reached the northern shore before going down.
This isn't the first time a medical flight has crashed in Lake Michigan. A Survival Flight plane carrying donor organs for a double lung transplant operation crashed in June 2007 into the lake near Milwaukee on its way to the University of Michigan Health System hospital in Ann Arbor.
All six people on board the Cessna 550 Citation were killed.