Milla Killeen was on her way to school on Wednesday when the bus rolled.

A schoolgirl killed in a bus crash outside Geelong has been remembered as a "beautiful soul" who was just days away from playing in her basketball final.

Year 7 student Milla Killeen was on a school bus with 27 other children on the way to her school when it rolled while turning at a bend near Stonehaven in Victoria's south on Wednesday.

She died at the scene and more than a dozen more students were injured and taken to hospital.

Watch: Milla Killeen mourned following fatal Stonehaven bus rollover.

Milla's family said they faced an anxious wait for answers before authorities confirmed the worst.

"We were made aware of the crash quite quickly, but it wasn't for several hours that our worst fears were realised — Milla was the one that was sadly taken," they said in a statement to media.

"She was a beautiful soul with the whole world in front of her."

They said they were struggling to come to terms with the loss of the 12-year-old.

"We don't know why this has happened," they said.

"It's difficult to describe all the emotions we feel right now, but we are supporting one another and now ask that our family's privacy is respected."

Her family remembered Milla as a keen student and athlete, compassionate friend and protective sibling to her younger brother.

"Milla was thriving at school where she loved learning new languages," her family said.

"Milla was very artistic, enjoyed drawing and designing lots of different things and she loved her sport.

"She used to play junior footy but lately had been focusing on basketball where she reached representative level and was about to play in a final on Friday night."

Milla has been remembered as a 'beautiful soul'. Image: Supplied.

Milla's basketball club, Try Boys Basketball Club, described her as a "cherished member" and "beautiful soul".

"Her absence will be profoundly felt by everyone who had the privilege of knowing her," it said in a statement.

"With her easygoing nature and infectious smile, Milla had a special way of lighting up every room she walked into. She quickly endeared herself to teammates, coaches, and the wider community.

"Milla will forever be remembered, not only for her talent, but for the kindness, warmth, and spirit she brought to all those around her."

Geelong United, where Milla represented the basketball under 14 girls 2 squad, said it was deeply saddened by the passing of the young athlete.

"Her love for the game, her teammates, and her bright spirit will be remembered by all in our community," the club said in a statement.

Christian College Geelong shared a tribute to the 12-year-old from Teesdale, remembering "her beautiful personal qualities, her vibrancy and infectious personality".

The keen and talented basketballer recently represented the college at the state championships and was described as a treasured member of the school community.

Her loss was deeply felt by all staff, students and families, Executive Principal Mathilda Joubert said.

"This is a time of unimaginable loss," Dr Joubert said.

"Our deepest sympathies and prayers are with Milla's family and our college will continue to provide ongoing support."

Investigations continue.

The bus was turning at a bend onto the Hamilton Highway when it hit a railing and rolled, with Detective Senior Sergeant Paul Lineham saying first responders faced a confronting scene.

It was transporting the 28 students, ranging from primary to secondary school age, to the college's junior, middle and senior Geelong campuses.

Two children, including a 16-year-old boy from Inverleigh, were taken to the Royal Children's Hospital and nine were in University Hospital Geelong suffering broken bones and skull fractures to milder injuries, Education Minister Ben Carroll confirmed.

The two children in Royal Children's were in a stable condition on Thursday.

The 76-year-old driver from Hamlyn Heights was also injured but was later released from hospital.

He has been interviewed by police and released pending further inquiries.

Investigators will assess the man's competency to drive and whether fatigue, drugs and alcohol or medical conditions played a role in the incident.

The bus will be mechanically examined. Detectives will look at the corner and what role the weather played in the crash.

Lineham said the bus had seatbelts but investigators were yet to determine where each passenger was sitting.

-with AAP

Feature image: Facebook/ChristianCollegeGeelong.