The mother of a 15-year-old boy who was killed in a stabbing at a Toronto high school said that no one had called her to let her know that her son was critically injured and was being taken to the hospital.

Grade 11 student Maahir Dosani was one of three teenagers who was injured in a stabbing outside of Victoria Park Collegiate Institute in North York around 3 p.m. on Tuesday.

He was found unconscious on school grounds by police with a stab wound to his torso and was rushed to hospital with critical injuries.

At the time, Dosani's mother did not know about what had happened. She told CTV News Toronto that she became worried when her son didn't pick up his phone after class was dismissed.

"I was trying to call him and he was not answering his phone, which is very, very unusual. He always answers his phone," Muskaan Dosani said.

"I messaged one of his friends who said ‘he's in the hospital.’"

Muskaan did not know what hospital her son was being taken to, so she started calling patient lines and someone suggested she try Sunnybrook Hospital.

When she arrived at Sunnybrook around 6:30 p.m., she says she was told her son had arrived without vital signs.

"We didn't get any calls from the hospital. Nobody called us," she said.

Half an hour later, police confirmed on social media that Maahir had succumbed to his injuries.

"We are still in shock," Muskaan said, fighting back tears. "We could never imagine that this would happen to my son because he was such a good kid."

According to his mother, the Grade 11 student was a sweet kid whose dream was to become a dentist.

The director of education with the Toronto District School Board (TDSB) reiterated Wednesday that Maahir "was a conscientious student who was respectful and engaged in class."

"We know that Maahir attended school on a regular basis and participated fully in the classes here at Victoria Park," Colleen Russel-Rawlins said.

The TDSB confirmed that all three stabbing victims—including a 16-year-old and a 14-year-old boy who were also found by police with non-life threatening stab wounds—attended Victoria Park Collegiate Institute.

Earlier in the day, a student told CP24 that prior to the stabbing, there was a large group of students gathering outside the school.

"Right after school there was a collection of 50 or so students just standing around the school and then after, about 20 or 15 minutes, they started fighting and then they just ran away when someone fell to the floor," the student said. "The ambulance came and that was it.”

Shortly after arriving on scene, officers took a 19-year-old man into custody in connection with the incident. On Wednesday, investigators identified the suspect as Toronto resident Ahmed Rafin and said he was charged with second-degree murder.

The suspect was a former TDSB student, the school board confirmed, but did not attend the same school as the victims.

Police have not said if the victims and the suspect knew each other and Muskaan told CTV News Toronto she did not recognize the suspect's name.

In a letter sent home to parents and guardians, the school's principal said that social workers and psychology staff would be on hand Wednesday to offer support.

"It is with deep sadness that we have learned of the death of a young person following a violent incident outside Victoria Park CI shortly after dismissal today," the letter, which was sent Tuesday evening, read.

"The TDSB will continue to work with the Toronto Police Service as needed throughout their investigation and would like to thank them and Toronto Paramedic Services for their assistance."

The school said that while police do not believe there is any further threat to the school or public safety, officers would be on school grounds Wednesday and will be available to anyone who may have information about what took place.

The Toronto Police Service's Homicide Unit is also asking anyone who may have photos or videos of the incident, or even the area before or after the stabbing took place, to contact investigators or reach out to Crime Stoppers anonymously.

With files from CTV News Toronto's Janice Golding