The incident happened around 5:30 at the Arco gas station on the 4700 block of Slauson Avenue, according to the Los Angeles County Sheriff's Department.
Deputies responded after receiving calls that customers had detained a man who was fighting with employees in the store, said Lt. Barry Hall.
The victim, identified as a 32-year-old employee of the store, was found on the ground behind the counter with multiple stab wounds. She was transported to a local hospital where she later died.
Further details about the man's identity and what prompted the stabbing were not immediately available.