DELANO, Calif. (KGET) — Kern Valley State Prison officials are investigating the death of an inmate as a homicide after he was attacked by two other prisoners.

Officials said officers responded to an attack on the maximum-security recreational yard at approximately 10 a.m. Thursday. Inmates Anthony Ramirez and Michael Caldera allegedly killed Sidney Kang with two inmate-manufactured weapons.

Kang was taken to the prison’s treatment center for treatment, but his injuries were so severe they required an ambulance to transfer him to a hospital. He did not survive his injuries and was pronounced dead at 10:41 a.m, according to a press release.

Kang was serving 14 years in prison for assault with force likely to produce great bodily injury, a second strike, inflicting great bodily injury and having a prior felony conviction of a serious offense.

Ramirez, 40, was serving a life sentence with the possibility of parole for second-degree murder with the use of a firearm and a 15-year concurrent sentence for intentional discharge of a firearm causing great bodily injury or death. He was also serving a 12-year sentence for assault by a prisoner with a deadly weapon or force likely to cause great bodily injury and a two-year sentence for possession and manufacturing of a deadly weapon by a prisoner.

Caldera, 35, was serving a 71-year sentence for several second-degree robbery convictions with the use of a firearm, a second strike, and resisting or deterring an officer with threats or violence, also a second strike.

This is the third inmate death at Kern Valley State Prison this year and the second recorded death this month. There was also a homicide investigation at Wasco State Prison.