Police are searching for a suspect in the death of a 15-year-old boy, fatally shot in a Toronto high school by a single bullet to the chest.

Students were locked down for several hours Wednesday afternoon as police searched C.W. Jefferys Collegiate Institute, until they were finally bussed to a nearby location and released to their families.

The shooting victim has been identified as Jordan Manners.

"The event that took place today is a very serious matter," said Toronto Police Chief Bill Blair. "A young student lost his life in this school, and it should be a safe environment for everyone."

There are reports that prior to the shooting there was a confrontation at a nearby strip mall. The fight then carried into the hallways of the school, where one person managed to acquire a weapon.

Manners was hit once in the chest while on the second floor of the school at around 2:30 p.m.

Police received a call about a possible drowning, but arrived at the school to find the teenage boy in a corridor suffering from a single gunshot wound.

The Grade 9 student was taken to Sunnybrook Hospital with serious injuries, but doctors were unable to save him.

Manners' mother arrived at the hospital a short while later and collapsed in tears after learning of her son's death.

No arrests have been made and police have not released any information about possible suspects.

Police and heavily armed tactical officers guarded the school Wednesday afternoon, but the area was not closed to traffic.

Parents arrived at the scene with little knowledge of the shooting, desperate for information. Many used cellphones to contact their children still inside.

One woman met the victim's mother outside the school, just as an official said her son had been shot. The mother fell to the ground with grief.

"I helped her up and then I found she was the victim's mom. She was unable to say a word," said the woman. "The nurse said one thing, and then I encouraged her, saying 'Be strong for your son, be strong for your son.'"

Friends and neighbours of Manners described him as a "sweet little boy" who turned 15 last Friday.

"I just feel sorry for the kid and his family," a neighbourhood friend who had known Manners since he was in kindergarten told the Canadian Press. "He just didn't deserve that."

Stu Auty, of the Safe School Network, said parents should be honest with the students about the situation and talk to them about the tragedy.

"Once you know the details, you explain the realities of the situation, the realities of the safety of the school," he said.

"And also, it's time to talk about values, what kids are doing today, and what kind of dangerous risks are out there."

The school has about 850 students and is located near the Jane and Finch corridor, a poor area of Toronto noted for years for its high crime rate.

The Toronto District School Board released a statement Wednesday evening, expressing its condolences to the family of Manners.

"We all feel a need to search for answers as to how and why this tragedy occurred, and there will be time to do that in the days and weeks ahead. But today we need to direct our collective compassion and support to the student's family, friends and the C.W. Jefferys C.I. school community," the statement said.

The school board added that counsellors will be at the school early Thursday morning to help students with the tragedy, and will remain as long as they are needed.

Provincial Education Minister Kathleen Wynne called the incident "every parent's nightmare."

"You react as a politician and a minister, but first you react as a mom," she told CTV Newsnet. "And you just can't imagine having this happen to your child. My heart absolutely goes out to the family. And as the education minister, I react with compete dismay that something like this could happen at one of our schools."

Officials at the scene cordoned off a large area surrounding the building. Former Toronto police officer John Muise, of the Centre for Abuse Awareness, said investigators always will try to expand the crime scene as much as possible.

"It's easy to make a crime scene smaller, but it's really difficult to make a crime scene bigger," he told Newsnet.

"Police recognize that, particularly with a shooting in a school, it can often be what we call a dynamic crime scene. So a suspect has entered the building, gone to a number of locations, potentially found a crime victim. There could be a blood trail, depending on the kind of firearm, and there could be shell casings left at the scene, and any variety of evidence."

He said that holding the students inside the school also keeps them safe, because it allows for greater control of the scene while police conduct a thorough search.

With reports from CTV's Lisa LaFlamme, Jim Junkin, Austin Delaney and John Musselman