FLORIDA (KFSN) -- The twin-engine plane was trying to take off from the airport in Bartow.
Authorities investigating the crash say it was very foggy around the Bartow Airbase early Sunday morning.
County Sheriff, Grady Judd Polk said, "One of our helicopter pilots was in the hangar, heard the plane starting to take off, and thought to himself my gosh, I can't believe someone is trying to take off in this weather. And he said it was just seconds later that he heard the change in the pitch of the blades and the impact at the north end of the airport."
Officials say the pilot, his daughters and their husbands were all aboard the plane.
All of them died in the crash.