SYLMAR, LOS ANGELES (KABC) -- An argument among friends escalated into a fatal stabbing of an 18-year-old man in Sylmar. An investigation is underway.



Authorities say the stabbing was reported at a townhouse in the 14000 block of Astoria Street at 8:15 a.m. by an acquaintance.



"The friend was not specific about what was wrong or even how he knew, but he was insistent," said Lt. Paul Vernon, commanding officer of the Mission Detective Division. "Officers believed it was a life-or-death emergency so they forced entry."



A group of co-workers were hanging out at a condo complex when two men started fighting. One man stabbed the other to death, police said. The victim lived at the townhouse with his mother and siblings, who weren't at home during the fight.



Police say the suspect is not in custody yet, but they know who he is.



Anyone with information is urged to call Det. Gretchen Schultz, Mission Homicide Unit, at (818) 838-9951.



