A 24-year-old prisoner died at the downtown Inmate Reception Center from injuries sustained during an apparent beating, authorities said Wednesday.
The identity of the man in Tuesday's attack, described only as Hispanic, has not been released pending notification of next of kin.
Cell cleaners found his body near a commode inside a large holding cell where 57 other inmates had been awaiting transfer to another facility, said Deputy Scott Butler of the Los Angeles County Sheriff's Department. 
Butler said the circumstances of the killing had not yet been established and that he could not speculate as to whether the assault was preventable.
The death at the county facility occurred Tuesday, just two days after a similar incident at the Men's Central Jail, where an inmate was beaten to death by two cellmates.
Men's Central Jail inmate Steven Prendergast, 32, died Monday at a hospital one day after deputies found him semi-conscious on the floor of his cell, bleeding from a cut to the head, Butler said.
The two cellmates who attacked Prendergast have been arrested and charged with assault.
Two recent reports have been critical of procedures in place at Los Angeles County jails, and of their effect on conditions for inmates.
According to a report released two weeks ago by a special counsel to the county Board of Supervisors, sheriff's deputies are potentially unable to control violent inmates because of inadequate training in the use of force.
The review found that deputies frequently don't receive formal training until sometime after starting work in the jail system.
An October report written by the Office of Independent Review, an independent watchdog created by Sheriff Lee Baca, cited the department for negligence in the handling of complaints from jail inmates involving deputies.