U.S. state troopers have launched an investigation after a Canadian tour bus overturned and slid down an embankment on a New Jersey interstate exit ramp Saturday morning, sending 23 people to hospital, including two children.

Nearly all of those injured have now been released from hospital, save for a few.

The bus, which left Toronto and was bound for New York City, was carrying 57-passengers including several children and an infant, according to authorities.

A spokesperson from St. Joseph’s Regional Medical Centre in Paterson New Jersey, told CityNews in an email that five patients (previously listed in critical condition) have been released from hospital while three more are now in fair condition.

The Associated Press reported that the driver, who suffered a gash on his arm, told state police that he had been cut off by another vehicle just prior to the crash.

Police were called around 7:45 a.m. after the chartered commercial bus with Ontario licence plates rolled over onto its side while on the Interstate 80 exit ramp in Wayne, N.J., about 25 kilometres northwest of New York City.

The crash caused some windows on the bus to shatter and the window frames pinned down three people, who were later freed.

“It was terrifying,” Norma Cumberbatch, 66, of Toronto, told The Star-Ledger of Newark.

Cumberbatch, who was travelling with her 68-year-old sister, Marjorie, said she struggled to free her legs from fallen luggage and other debris before trying to find her sister.

“I just took my leg out and then said, ‘Where’s my sister? I want my sister.’”

Marjorie Cumberbatch said she heard “thump, thump, thump. Then I looked up and I saw people over me screaming and crying.”

A passenger told the Associated Press that at first, she didn’t realize what was happening.

“I just hear the glass cracking, cracking and then I look I saw, I saw, my god, what is this? You know and I was laying on the floor,” said the woman who was not named.

Another female passenger had been sleeping when the collision occurred.

“I had just gotten up from sleeping and so, you know felt the commotion and then all of a sudden, you knew the bus had turned over,” said the woman.

Other witnesses reported seeing passengers waiting along the side of the exit ramp while they were being treated and several people wearing neck braces being loaded into ambulances.

Those who were unhurt were put onto another bus and continued with their journey, according to authorities.

A dispatcher from AVM Max 2000 Charter Services Inc. in Toronto confirmed Saturday that the bus was headed to New York City. It’s unclear when it had left.

The bus had been chartered by a group of Seventh Day Adventists who were headed to an event in Brooklyn.

Photos from the scene show the bus on its side at the bottom of the embankment that the ramp wraps around.

It’s not immediately clear what caused the bus to flip over. The exit ramp was shut down for several more hours.

Those Canadians concerned their relatives may have been in the crash can call Ottawa’s Department of Foreign Affairs at 1-800-387-3124 or email orsos@international.gc.ca.