Initial investigations showed the helicopter had sustained significant damage and several pieces were likely missing, Hersman said.

The helicopter took off about noon Saturday from a heliport on 30th Street for the sightseeing tour as the Piper was making its way south along the Hudson from the Teterboro airport outside New York City toward Ocean City, New Jersey.

Hersman said Saturday that another Liberty helicopter pilot saw the approaching accident and tried to warn the pilot, before seeing the plane make contact with the helicopter.

The debris fell into the Hudson River somewhat north of the Statue of Liberty in New York Harbour.