CHARLESTON, W.Va. (AP) — Federal officials say the helicopter carrying coal billionaire Chris Cline began spinning before it plunged into the ocean near the Bahamas and killed everyone on board.

The National Transportation Safety Board on Tuesday released a preliminary report that details the July 4 accident and its aftermath but doesn't include a cause. Cline, his daughter Kameron and three of her friends died along with a pilot and copilot in the crash off Cline's private Big Grand Cay island.

The report says a witness saw the helicopter rotate to the left three to four times, followed by a whooshing noises and the sound of an impact. It was found upside-down with several broken pieces.

The NTSB says the aircraft was leaving the island to take two passengers to Florida for medical treatment.