The crash happened at 12:30 a.m. Friday in the southbound lanes near mile marker 19.
VIDEO: Exclusive interviews with passengers who were on the bus
VIDEO: Passengers describe tour bus crash on NJ Turnpike
A Panda tour bus with 50 people on board was heading from New York City to Atlanta when it collided with a tractor-trailer.
The bus rolled onto its side and ended up in a grassy area off the shoulder of the highway.
The cab of the Performance Food Group tractor-trailer appeared to have nearly detached.
VIDEO from the Action Cam at the crash site
Tour Bus Accident On NJ Turnpike
Thirty-three people who were on the bus were taken to four area hospitals to be treated for injuries.
Several were taken to Inspira Medical Center in Woodbury, N.J.
VIDEO: Passengers arrive at Inspira Medical Center in Woodbury, N.J.
Tour Bus Crash Victims Rushed To The Hospital
Other injured people were taken to Cooper University Hospital in Camden.
It was not immediately clear if the bus driver was among those injured.
Action News is told some of the injuries were serious, but most were minor.
VIDEO: 911 call reporting NJ Turnpike tour bus crash
911 call from NJ Tpk. crash
Some of those who were not hurt were taken to the Woolwich Township Municipal Building.
Action News spoke exclusively to several of those passengers.
"The bus started flipping, then flipped over," said Dwight Baylor of Brooklyn, N.J. "I fell on my back... and they were trying to help me up."
"I heard somebody say, 'Oh, no! Oh, no!' and then a boom," said Lucy Mongy from Harlem, N.Y. "And then I felt like it was correcting direction. And then I heard another boom, and then we started tipping. And then I told my sister, who was next to me... I said, 'Relax your muscles.' Because, you know, they say to do that."
The driver of the tractor-trailer was not injured, and was interviewed at the scene by investigators.
New Jersey State Police closed all southbound traffic at exit 4 after the crash.
All lanes had reopened by 4:30 a.m.
The cause of the crash remains under investigation.