"The victim was later transported via helicopter to the Albany Medical Center where she remains in stable condition with no serious injuries reported".
The teen from DE struck a tree before landing in the crowd, which had gathered to catch her.
The girl was riding the attraction with a younger relative and fell about 25 feet from a stationary two-person auto, the sheriff's office said in a statement.
Witnesses first spotted the girl hanging from the chair by her arms and head.
"I'm just glad we could be there to help", Winchell said. A 47-year-old involved in helping to catch the teenager suffered from a back injury, and was treated at a hospital.
A gondola glides over Six Flags Great Adventure amusement park in Jackson, New Jersey.
The slow-moving ride had been halted after reports of someone in distress.
The Warren County Sheriff's Office said the girl, from Greenwood, Delaware, fell from the vehicle and struck a tree before landing in the crowd.
"The safety and security of our guests is our top priority", park spokeswoman Jessica Hansen told the Post-Star in an email.
The ride will be closed until the park can do a thorough review of what happened.
When asked whether the girl's evacuation from the ride had followed protocol, Wood did not specify but said that all rides have a "standard evacuation plan". They did not know how she had fallen out of the ride.
Officials inspected the Sky Ride and said it was in proper working order. "We are reviewing our internal procedures to ensure the safety and security of our guests and team members".