The shooting happened in the 400 block of West Magnolia Street around 1:30 a.m. in an alleyway behind an apartment building where a group of young men gathered to socialize. A man then walked up and opened fire on the group, hitting three people.
One person was declared dead at the scene and two others were rushed to the hospital.
Lt. John Corina with the Los Angeles County Sheriff's Office says a hunt is underway for the lone gunman, who reportedly fled on foot.
Deputies say there were several witnesses present at the time of the shooting. They will be interviewed as part of the investigation.
There is no suspect description at this time. The victims have not been identified.