The stabbing happened as 15-year-old George Sosa and his 16-year-old friend were walking home from Norwalk High School Friday.
Authorities said two suspects got out of a car and the passenger stabbed the two victims.
Both victims were rushed to an area hospital, where Sosa was declared dead. His friend was listed in stable condition.
Family, friends and neighbors gathered Saturday night to remember Sosa.
"Two families are destroyed now. One lost their loved one, and another one will lose a loved one once he goes into justice. It's very sad for both families," said Norwalk resident Anna Ibarbol.
Authorities are still searching for the driver of that car. They say it all started after a fight at school between Sosa and one of the suspects.
If you have any information regarding the whereabouts of the second suspect, you're urged to contact the Los Angeles County Sheriff's Department Homicide Bureau at (323) 890-5500.