The Miami Herald reported the crash occurred shortly after 4 p.m. near the city's executive airport.
Witnesses told the newspaper the twin-engine Piper aircraft destroyed seven vehicles and a boat.
"The plane is in pieces," Fort Lauderdale Fire Rescue Division Chief John San Angelo said. "There are car parts and plane parts everywhere."
He said no one on the ground was hurt.
The names of the victims were being withheld until their relatives could be notified.
The Herald said there were television reports that those killed may have been pilots taking the plane out for checks. San Angelo said the plane appeared to experience trouble soon after takeoff and tried to return to the airport.
Dozens of firefighters worked to extinguish the fire that resulted from the crash.