The sightseeing flight, operated by Liberty Helicopters for FlyNYON, operated with its doors off and allowed passengers to slide toward the open door and dangle their feet outside the helicopter. The NTSB investigation determined that a safety harness had become caught under the fuel shutoff lever when one passenger slid toward the open door, effectively cutting off the engine 1,900 feet above the city. The pilot stated that he noticed the fuel shut-off lever had been moved to "off" and that the passenger's tether was under it. After pushing the lever to "on", the engine began to restart, but it was too late to avoid hitting the water. The emergency flotation devices on the skids of the helicopter also malfunctioned, flipping the helicopter instead of allowing it to float, and the open doors quickly flooded the helicopter, submerging it in just 11 seconds. As the FlyNYON sightseeing helicopter rolled upside-down, the pilot swam to the surface while the passengers remained tethered to the aircraft. All five passengers were killed.

After the crash, the FAA moved to prohibit doors-off flights that did not use FAA-approved harnesses that did not require outside assistance to unfasten in event of an emergency. The passengers in the FlyNYON crash were wearing harnesses that were "comprised of off-the-shelf components" and the tethers were attached at both ends with locking carabiners that were meant to be unscrewed by employees to release passengers after the flight. The tethers could not be removed in time by the passengers as the helicopter sank, and rescue divers had to cut them free to recover them from the wreckage.

Killed in the crash were Trevor Cadigan, 26, a video journalist from Dallas; Brian McDaniel, 26, a firefighter from Dallas; Tristan Hill, 29, who worked at Sightsy, a sightseeing tour company; Carla Vallejos Blanco, 29, who was visiting the city from Argentina; and Daniel Thompson, 34, who worked for the company that operated the flight.