PARAMUS, N.J. (WCBS 880) -- Video of the deadly New Jersey school bus crash apparently shows the bus driver attempted a U-turn by turning from an access road across the interstate when it was hit by a dump truck. 

The video from the New Jersey Department of Transportation has not been made public, but a source who watched it tells CBS News the bus got off at the exit for Waterloo Village, where the East Brook Middle School students were heading on a field trip, but the driver made a wrong turn and headed back to Interstate 80, WCBS 880's Alex Silverman reported. Then instead of merging onto the highway, he tried to make a sharp left from the accress road across three lanes of traffic toward a turnaround that's restricted to official vehicles. At that point, a dump truck traveling westbound crashed slammed into the rear of the bus, separating the cabin of the yellow bus from its chassis.

The bus flipped on its side over a guard rail and came to rest on the grassy median in Mount Olive. 

Police outside, grief counselors inside as students return to EastBrook Middle School on an incredibly difficult day. A teacher, Jennifer Marie Williamson,50, and a fifth grader killed in I-80 school bus crash. pic.twitter.com/QPF4IRt96s

— Marla Diamond (@MDiamond8) May 18, 2018

PHOTOS: Deadly New Jersey School Bus Crash

There were 38 fifth grade students and seven adults, including the driver, on the bus.

A student who was on the bus said, "I heard a scraping noise and then the bus tilted over. A lot of them got cuts and scrapes, a few of them got out of the windows and they got out of the emergency exit on the top on the roof."

Mourning at East Brook Middle School in Paramus. Victim identified as 50-yr old Jennifer Williamson, a fifth grade teacher. Student who died is a fifth grader. Several other students remain hospitalized. Grief counseling available. @wcbs880 pic.twitter.com/tX93UJxktM

— Marla Diamond (@MDiamond8) May 18, 2018

Jennifer Marie Williamson, a popular social studies teacher, was killed. She grew up in Paramus. Her father died when she was a child and her brother died in a car wreck in the 1980s.

Her husband released a statement along with photos of his wife on the day of their wedding saying, “My beautiful bride and I have been in total love every day of our lives since the day our eyes met on 5/5/94. I am in shock, devastated and totally crushed by today's tragedy to both sides of the Willamson-Kennedy families, the community she taught and the thousands of students and their families she was very proud to serve.”

The fifth grade student killed in the crash has not been identified. Her twin sister was on the field trip in another bus.

Several students remain hospitalized.

Grieving parents and students have placed bouquets of flowers and notes under the East Brook Middle School sign. Grief counselors were at the school Friday morning to help the school community cope with the tragedy.

Students, parent, staff return to East Brook Middle School. One student said she thought about staying home, but said she wanted to be here to grieve with friends. Teacher identified as 50-year old Jennifer Williamson. @wcbs880 pic.twitter.com/bqopqN3tal

— Marla Diamond (@MDiamond8) May 18, 2018

"She was definitely one of my favorite teachers, she cared a lot about every student that she had," a 13-year-student said of Williamson as she arrived at school Friday. "I didn't know if I was going to come in. I just wanted to see all my friends."

Marissa, a 6th grader ay Eastbrook Middle School says she wants to be with her friends to mourn the tragedy. Investigators say School bus may have made illegal u turn on #I80 @wcbs880 pic.twitter.com/uIXE0sfjk5

— Marla Diamond (@MDiamond8) May 18, 2018

"I fell like everybody's going to be crying, which when other people cry I cry," said Marissa, a sixth grader who said she wants to be with her friends to mourn the tragedy. "A lot of my good friends were on that bus and it's scary to think about what happened."

Purple ribbon outside East Brook Middle School in Paramus. Teacher killed in bus crash ID’ed as 50 yr old Jennifer Williamson, a 20 yr teaching veteran. @wcbs880 pic.twitter.com/P0WUkIZR2W

— Marla Diamond (@MDiamond8) May 18, 2018

The trucking company, Mendez Trucking in Belleville, has 247 safety violations over the past two years, 13 driving citations and eight accidents.

There has been no word from prosecutors on what charges might await the driver who worked for the Paramus board of education.