The plane was traveling from the Bahamas to Junction City, Kan., when it went down Thursday near Lake Wales, The Palm Beach (Fla.) Post reported.
The cause of the crash was not known.
Officials said Ronald Bramlage, 45, was piloting the plane, and his wife Rebecca, 43, and their four children were on board.
The Federal Aviation Administration's Web site indicated the plane was a Pilatus PC-12/47 registered to Roadside Ventures LLC of Junction City, owned by Ronald Bramlage, MSNBC reported.
Officials said parts of the plane were found 2 miles from the crash site.
The plane was the same one Casey Anthony, acquitted last summer of the major charges in the 2008 death of her 2-year-old daughter Caylee, flew in when she left Orlando after being released from jail. It was owned by Anthony's former attorney, who reportedly may have sold it this year.
KSN.com reported Rebecca Bramlage was president of the Junction City Board of Education. The couple were active alumni of Kansas State University, where Bramlage Coliseum is named for Ronald Bramlage's grandfather.
"We are shocked and saddened by the tragic news of the deaths of Ron and Becky Bramlage and their children today," KSU President Kirk Schulz and Athletics Director John Currie said in a statement. "The Bramlage family holds a special place in the history of Kansas State University and K-State Athletics, and Ron and Becky have been loyal supporters and great fans of K-State. Our thoughts and prayers are with the Bramlage family during this difficult time."