National Transportation Safety Board investigators are trying to determine the cause of an airplane crash that killed Tampa businessman Daniel Dorsch and his wife, Cyndie Dorsch.

Air traffic controllers received a distress call at 10:06 a.m. Sunday from Daniel who said an exterior panel on the Pilatus PC-12 fell from the plane. The turboprop was en route to Tampa Executive Air Center from Teterboro, N.J., when it crashed. Investigators have said a flight plan shows five people were on board.

Daniel, whose business interests included the 66,000-square-foot Fun Bike Center on Memorial Drive in Lakeland and Papa John’s Pizza franchises, was chief executive officer of Checkers Drive-in Restaurants Inc. from 1999-2003.

A Dorsch family spokesperson confirmed Daniel and Cyndie Dorsch were killed in the crash. They had a home in Tampa Palms, according to property records.