(CNN) -- A French-Moroccan family of five was killed Saturday when their plane crashed near the French Alps, authorities said.
It was not immediately clear why the twin-engine plane went down. Everyone aboard died -- a man, his wife and their three children -- Virginie Favier, a local police captain, told reporters.
The family had been returning to Morocco after spending their holiday in the French Alps, she said.
Gilles Rabault, another police captain, told reporters that the plane disappeared off the radar and crashed shortly after takeoff from an airport near the southeastern city of Grenoble. Emergency workers responded after a resident reported the crash.
"We felt a big shake. The crash happened just below my house. At the beginning, I did not know what it was. We found out after firemen came that it was a plane crash. We did not see the wreckage," a witness, identified only as Leo, told CNN affiliate M6.