The two men were stabbed during a fight outside a home at 136 Rainbow Cres. near Erin Mills Parkway and Burnhamthorpe Road around 1:30 a.m. on Saturday, according to Peel Regional Police.
Zack Jelovsek, 19, has been identified as the deceased vicim. He was found on the ground when police arrived. An officer performed CPR, but Jelovsek later died in hospital.
The other victim, 20, was taken to hospital with non-life-threatening injuries. It's not clear if the two men knew each other.
Hamza Othman, 19, and Ilir Memedovski, 20, have been charged with second-degree murder. Neil Patel, 20, was charged with accessory after the fact.
All three are from Mississauga.
Memedovski appeared in court on Saturday and was remanded into custody. Othman and Patel are expected to appear in court in Brampton on Sunday.
Large crowd at party
Neighbour Amanda Avery told CBC News she spotted a group of party-goers a few doors down from her house around midnight. An hour later, the crowd had grown dramatically and soon, was fleeing frantically across her front lawn.
"All of a sudden it became hysterical screaming," Avery told CBC News. "I looked out the window and there was about a hundred kids just flocking."
From another window she saw young girls hiding behind her car, "crying on the ground, curled up in little balls."
There was such a large crowd at the party, officers called in city buses to take witnesses to a nearby police station.