Family members and classmates of a 10-year-old boy killed in a school bus crash on a Brampton, Ont. highway are struggling to cope with the loss of the friendly and well-liked child.

John Pham died late Wednesday night at Toronto's Hospital for Sick Children after suffering a serious head injury that left him brain dead.

John was one of about two dozen Grade 4 students on the way to a field trip at an outdoor education centre when the bus they were riding in sideswiped a tractor-trailer and went into the grassy median on Highway 410, northwest of Toronto.

Relatives gathered at the boy's apartment, consoling each other and trying to come to grips with the tragedy.

John had been looking forward to the field trip for weeks. He had circled the date on his calendar and promised to tell his baby sister Sophia all about it when he got back.

"He never made it. He's gone," said his aunt Mai Pham, fighting back tears.

"He was just a really kind kid," said cousin Giang Nguyen, overcome by emotion.

Grief counsellors attended St. Alfred Catholic School in Mississauga on Thursday to help children cope during the ordeal. The flag outside the school was lowered to half-mast.

Parents of students were also shocked and saddened by the news.

"It's absolutely tragic, very hurtful," said one father.

"My heart just dropped, and then I thought of the kids and the parents," said one woman, who broke down in tears.

A special prayer service will be held at the school on Friday.

A nine-year-old girl suffered a serious broken leg in the crash, while about a dozen other children received minor bumps and bruises.

John's classmate, Karol Swiatowiec, was one of many students who stayed home on Thursday. Karol described the horrific crash to CTV News.

"There was a big bump and all of the kids jumped up. Some of them hit the ground, some of them hit the windows," the shaken boy said.

"When there was a bump, there was a lot of screaming, and when we stopped, there was a lot of crying."

Karol saw John lying unconscious on the floor of the bus after the accident.

Police believe John violently struck his head during the crash. He had no vital signs at the scene but was resuscitated at Peel Memorial Hospital and then taken to Sick Kids Hospital.

Four adults on board the bus -- the driver, two parents and one teacher -- were also treated. The driver remained in hospital on Thursday. She reportedly suffered minor injuries.

Pat Pringle, the driver of the tractor-trailer, was not hurt.

The investigation

Investigators believe the bus driver may have been attempting to pass the truck and she may have misjudged her distance, clipping the truck.

Police say it is far too early to determine if charges will be laid. Their investigation, which will include scene reconstruction and a mechanical check, is expected to take a few months.

The company that owns the bus, Laidlaw Transit, issued a statement on Thursday.

"A tragedy such as this affects families, our employees and the community, and our sincere thoughts and prayers go out to all. We are working closely with authorities in their investigation, and also are conducting our own internal investigation of the accident."

A Laidlaw worker who didn't want to be identified says the company's review may focus on whether the kids were seated and if there were enough adults on board -- one for every six students is recommended.

Transport Canada is also reviewing the accident.

Seatbelt debate

The accident has reignited the debate in Ontario over mandating the use of seatbelts on school buses.

While Ontario Premier Dalton McGuinty offered his condolences to the family and friends of the boy, he stressed that federal government officials continue to advise against putting seatbelts on buses.

"The very best advice that we're getting is that it is safer for our children not to have them in seatbelts,'' McGuinty said.

"We will certainly use this as another opportunity to review safety features of our buses."

Ontario's transportation minister Donna Cansfield said Wednesday she would review the use of seatbelts on school buses.

Arguments in favour of seatbelts say it is safer to strap children in the seats to keep them from being thrown around during a collision or rollover.

The large seats commonly found on school buses are believed to provide protection during impacts. During rollover accidents, however, children are left vulnerable.

Brian Patterson, president of the Ontario Safety League, agrees buses are safer without seatbelts.

"After looking at engineering reports over the last two years, I'd have to say no, I wouldn't put seatbelts in," Patterson told CTV News.

Ontario school buses transport about 800,000 children every day, and Cansfield says they have a very good safety Record.

With reports from CTV's Chris Eby and Roger Petersen and files from The Canadian Press