Nearly a dozen people suffered minor injuries Monday during an annual Fleet Week demonstration on Staten Island.
U.S. Marine Corps officials say an MV-22 Osprey aircraft was landing in Clove Lakes Park around 8 a.m. when its powerful twin engines began kicking up dirt and debris over a shaded spectator area.
The force knocked over part of a tree causing people to scramble away as their picnic blankets and other belongings were swept up.
Seven people were treated at Richmond University Medical Center, but officials say their injuries were minor.
Several others were treated at the scene.
"I saw blankets flying everywhere, and people running it was nerve wracking," said one witness.
"It produced such a downward thrust that it basically ripped apart a tree, sending approximately 10 heavy limbs to the ground, and blew some people off their feet and that was the cause of the injury," said New York City Fire Department Battalion Chief Dan O'Gara.
The U.S. Marines Corps is investigating the incident. But according to initial findings, the pilot followed safe procedures while landing.
"We maintained our 150 feet minimum but that down rotor was still able to snap that tree limb off. So we're just very, very fortunate and very pleased that nobody is hurt anymore than some scratches and cuts," said Colonel Eric Smith of the 8th Marine Regiment.
The U.S. Navy says the rest of the marine air and ground demonstrations are going on as planned.