A teenage boy is dead in Oshawa after being stabbed in a fight, one witnessed by a number of his horrified peers.

"I stood on a garbage can so I could see everything happen. The two guys were supposed to fight, and then he had him against a wall, and then ... I don't even want to say," said Kendal Wood, a friend of the victim, on Tuesday.

Wood's mother then gave her daughter a comforting hug. Kendal also had this thought: "To watch someone get killed -- It hurts."

Durham Regional Police said they were called to the intersection of Stevenson and Rossland Roads in Oshawa at 2:22 p.m., which is near a busy bus stop.

They found the 16-year-old suffering from a stab wound. One witness said it started as a regular fist fight -- and then one person pulled out a knife.

Paramedics rushed the boy to hospital, where doctors pronounced him dead.

The student was enrolled at nearby Monsignor Paul Dwyer Secondary School -- as was his alleged 18-year-old assailant, who was arrested in the nearby vicinity shortly after police arrived. There are claims the two had fought in the past.

Others told CTV Toronto the shocking incident left many in tears, with one saying he couldn't believe such a thing happened. Another wondered if they will even be going to school on Wednesday. School officials say there will be counsellors available for students.

The 18-year-old is under arrest and being interviewed, but he has not been charged yet. CTV Toronto reported late Tuesday that a formal charge will likely be laid on Wednesday morning.

Durham Police say this is the fourth homicide in the region so far in 2010. They are withholding the victim's name until they have notified his family.

Friends have identified the victim as Mike McDonald, a football player some called "Biggy."

His parents were among those who came to a growing shrine at the scene of the slaying. His mother said when she got the call from one of her son's friends, she hoped it was just an arm wound or something similar. The teen's father said his son "had things going" and was hoping for a scholarship.

With a report from CTV Toronto's Michelle Dube