A twin-engined Piper aircraft went down into Lake Okeechobee near Pahokee Airport in Florida, local media CBS12 reports.
The plane had previously taken off from Tampa International Airport.
One person was seen swimming away from the aircraft, it has been reported.
Palm Beach County Sheriff said: “PBSO Marine Unit Deputies and Palm Beach County Fire Rescue personnel recovered five individuals from the aircraft fuselage.
“All individuals are deceased.”
Rescue divers from Palm Beach County Fire Rescue reportedly recovered five bodies from the plane.
The plane reportedly went down around 3.30pm EST (8.30pm GMT).
The Federal Aviation Administration are investigating the crash.
The weather was not believed to be a factor in the crash, according to Spectrum News.
The outlet said the plane was commonly used as a training plane.
Pahokee Airport, which was 400 yards away, does not have a control tower, Spectrum News reports.
The news follows another small plane crash in Florida on March 6.
A student pilot was killed when travelling from Vero Beach Regional Airport to Palm Beach County Glades Airport in a Piper PA-28.
The Indian River County Sheriff’s Office said the Piper PA-28 Cherokee disappeared shortly after takeoff, and the crash was spotted in a wooded area by a sheriff’s office helicopter pilot about 90 minutes later.
Officials didn’t immediately identify the pilot, but a FlightSafety International spokesman confirmed that the pilot was their student. No one else was aboard the plane.