An inmate died in his cell Sunday at the federal penitentiary in Lompoc, prison officials announced Monday morning.

The inmate, whose name was not released, was reportedly found unresponsive in his cell around 4:20 a.m. Sunday. Staff immediately called for assistance and began life-saving measures, according to the prison, but the inmate was subsequently pronounced dead by Emergency Medical Services personnel.

The FBI was notified and the incident is being investigated, prison officials reported.

The name of the deceased inmate is being withheld pending notification of next of kin, according to the prison.

The U.S. Penitentiary Lompoc is a medium security facility that currently houses 1,282 male offenders.

Additional information about the Federal Bureau of Prisons can be found at www.bop.gov.