At 12:50 p.m. Eastern Time, a Learjet 60 crashed in a neighborhood near Cresthaven, FLorida, Duffy said in a post on X. "All nine people on board were killed," Xinhua reported.
The aircraft departed from Austin, Texas and was bound for the Bahamas, he added, calling the crash a "horrific tragedy."
The Federal Aviation Administration is sending a team to the scene to support the National Transportation Safety Board investigation, Duffy said.
It was unclear if anyone was hurt on the ground.
Minutes before the crash, the pilot of the plane reported ice accumulating on the aircraft and moderate turbulence, according to a recording of air traffic control radio calls captured by LiveATC.net.
Moments later the plane declared an emergency and plunged about 8.2 km in one minute.
There were scattered storms in the area at the time of the crash, and the plane passed through a stronger storm cell a few minutes before it began descending, local media reported.
Video of the crash showed the aircraft nose-diving from the sky and erupting into a giant flame ball near a major roadway, creating a crater.