The accident killed a Spanish family of five, including Agustin Escobar, chief executive of Rail Infrastructure at Siemens Mobility, the train transportation arm of Germany-based technology company Siemens.
The NTSB said it had validated evidence of a bird strike on the Bell 206L-4 tourist helicopter.
The airspace around Manhattan is crowded with helicopters offering tourists a bird's-eye view of the sights, with at least two dozen operators listed on tour website Viator.
Many operators also offer helicopter shuttle services to the area's airports.
The flight was the eighth tourist flight of the day, heading from the Statue of Liberty to the George Washington Bridge, which was followed by a turn south to fly above the Hudson River.
Multiple witnesses described hearing loud "bangs" and "pops" from the helicopter before it broke up and descended into the river.
An additional witness reported that just minutes before the accident, she saw a large flock of geese take flight near the Newport lighthouse in Jersey City, New Jersey.
"When the helicopter went bang, I immediately thought it was a bird strike," the NTSB report said.
In 2018, five passengers aboard a helicopter died in New York when the aircraft crashed into the East River, although the pilot survived.
The helicopter was on a charter flight that featured an open door to allow passengers to take photographs of the skyline.
Regulators turned their focus to helicopter safety after 67 people died in the crash of an American Airlines regional jet and army helicopter in January 2025 near Reagan National Airport in Washington DC.
The FAA has permanently restricted helicopter traffic near that airport and imposed other restrictions on helicopter traffic around the country.
