Passengers struggled to escape safety harnesses as a sightseeing helicopter sank in New York City's East River last year, according to a newly-released report.

Video recorded aboard the open-door aircraft shows one passenger trying to move his shoulder strap and another reaching for a hook knife, a National Transportation Safety Board report said.

"How do I cut this?" one passenger asks, 13 seconds before the video goes black under water.

Divers recovered five passengers from the submerged plane, and they all died following the crash. The pilot freed himself, officials said, and survived after being rescued by tugboat.

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The board released a transcript of the video Monday in preparation for a meeting to determine the crash's cause, but did not provide the footage. A Go Pro camera mounted on the cabin ceiling recorded the sightseeing tour and the eventual crash.

Passengers could be heard laughing and joking before the sightseeing tour started, according to the transcript. The helicopter lifted off the ground at 6:53 p.m., investigators noted, and hit the water about 14 minutes later. One passenger could be seen typing a caption on Snapchat less than a minute before the sudden impact.

The aircraft was owned by Liberty Helicopters, a company that offers both private charters and sightseeing tours popular with tourists.

A public National Transportation Safety Board meeting to determine the cause of the crash is scheduled in December.

Contributing: Jane Onyanga-Omara, The Associated Press