The incident happened at about 10:30 on Maple Drive in New Hyde Park.
Police say the injured include a 30-year-old man who sustained a fractured right leg, a 43-year-old woman with a large contusion to the right side of her face, a 44-year-old woman with a laceration to the top of her head, and a 40-year-old woman with an abrasion to her forehead and back and shoulder pain. None of the injuries were life-threatening.
"My children were there, I couldn't find them, it was horrible, the kids, we didn't know if they were under the tree, we tried to lift the limb," said eyewitness Alissa Coogan.
Things on Maple Drive went from bad to worse in a matter of seconds. What started out as a peaceful block party on Saturday night turned into a chaotic scene.
"It just came out of nowhere, it was really scary, it was a quiet beautiful day," said eyewitness Darren Olivieri.
The partygoers' only warning was what sounded like fireworks going off ? it was actually the eerie sound of splintering wood. The enormous tree branch cracked and then fell straight down onto roughly 30 people.
"There were 30 of us and we couldn't get it up at first and then we all shifted the big truck of it and lifted it," adds eyewitness Danny Kilcullen.
Underneath that branch was a 30-year-old man with a severely broken leg and young mother who had lost consciousness but was alive. Also in the darkness and confusion - a group had been playing a game right in the exact spot. Many people feared the worst.
The tree sits on private property, but people living on the property fear, that an incident like this will happen again. There are dozens of oaks in the neighborhood, known for the towering beauties.
Eyewitness David Cushman said he has called the town about his tree several times, and it has been tagged to come down.
"Mine is only one of 7000 trees, and they'll get around it, it could take 3 years," notes Cushman.
Many other oaks took a beating during Superstorm Sandy.