MOUNT OLIVE, N.J. -- A school bus taking fifth graders on a field trip to a New Jersey historic site collided with a dump truck Thursday morning in a "horrific" deadly incident. Officials said there were two confirmed fatalities in the crash, which ripped the bus apart and knocked it on its side.

One of those killed was a teacher and the other was a student, according to officials. The body of the bus came completely off its chassis and was resting on its side in the highway median.

"I have never seen anything like that. I can only describe it as horrific," said Mount Olive Mayor Robert Greenbaum, CBS New York reported.

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The bus was carrying fifth grade students from East Brook Middle School in Paramus. They were on a field trip to Waterloo Village, which depicts a Lenape Indian community and once-thriving port along the Morris Canal. It is a popular site for school trips.

"I heard a scraping sound and we toppled over the highway," said student Theo Ancevski, who was sitting in the fourth row of the bus and was treated at a hospital for cuts and scrapes. "A lot of people were screaming and hanging from their seatbelts."

Some of the victims in the crash, which occurred around 10:20 a.m. ET, crawled out of the emergency exit in the back of the bus and an escape hatch on the roof. Some children were still inside the bus when first responders arrived, according to Jeff Paul, director of the Morris County Office of Emergency Management.

"We had patients laying all over the median and on the interstate," Paul said. "There were all kinds of injuries, every injury type you could expect in a crash of his magnitude."

There were 38 students and 7 adults on the bus including the driver, according New Jersey Gov. Phil Murphy, who spoke at a press conference Thursday. A total of 43 people of those 45 were injured and transported to hospitals for treatment, he said. The bus was equipped with seat belts.

Paul said some of the first responders were "very emotionally upset. It was a rough scene to see."

Students on two other buses on the field trip returned to the school Thursday morning and were reunited with their parents, said Paramus Police Commissioner Holly Tedesco. A sign outside of the school, about 50 miles from the crash site, informed people to go to the auditorium for updates on the accident, and the school was offering crisis counseling.

Seventh-grader Alejandro Garcia told The Record that students were told to return to homeroom on Thursday morning. As his classmates started searching online to see what had happened, they realized there had been an accident.

"People who I'm close friends with, who have brothers and sisters on that bus, started crying, and everybody just started sympathizing," Garcia said. "It was just a time of need for everyone."

This morning, East Brook Middle School students on their way to Waterloo Village were involved in a serious bus accident... Posted by Paramus Public Schools on Thursday, May 17, 2018

The front end of the dump truck involved in the crash was mangled, and the condition of the truck driver wasn't known. The truck involved was registered to Mendez Trucking, of Belleville, and had "In God We Trust" emblazoned on the back of it.

Mendez Trucking has 33 drivers and 33 trucks, according to the Federal Motor Carrier Safety Administration. Police did not immediately comment on the cause of the crash. Mendez trucks have been in seven crashes in the last two years, none of them fatal, according to FMCSA.

Mendez was fined $22,850 in 2016 for violating regulations on inspections, repairs and maintenance and post-crash drug and alcohol testing, according to the FMCSA. Mendez has a higher than average vehicle out-of-service rate, which means inspections found violations which had to be corrected before the vehicle could be returned to service. Mendez's rate was 37.9 percent, according to FMCSA. The national average is 20.7.

A message left with the company Thursday wasn't immediately returned.

Victims of the crash were taken to Morristown Medical Center, St. Joseph's Health, St. Clare's Dover Hospital and St. Clare's Denville Hospital. Information on their exact condition wasn't released.

The National Transportation Safety Board said it was gathering information on the crash. The New Jersey State Department of Health's disaster team was on the scene to assist with family reunification and counseling.