The shooting was reported just after 4:25 p.m. in the 8600 block of Graham Avenue, near Firestone Boulevard and Metro Rail's Firestone Station, according to the Los Angeles County Sheriff's Department.
The man was pronounced dead at the scene by paramedics. His name was withheld pending notification of his next of kin.
No suspect description was immediately available.
Authorities asked anyone with information on the shooting to call the Sheriff's Homicide Bureau at 323-890-5500. Anonymous tips can be called in to Crime Stoppers at 800-222-8477 or submitted online at lacrimestoppers.org.