OTAY MESA (CNS) - A 70-year-old jail inmate died under suspicious circumstances in his cell at the George Bailey Detention Center early Monday, authorities said.

The man, whose name was withheld pending family notification, was found unresponsive at the Otay Mesa lockup facility shortly before 2 a.m., the county Medical Examiner's Office reported.

Medical staffers tried to revive him before pronouncing him dead in a common room at the Alta Road jail.

Sheriff's homicide detectives conducting a routine investigation into the fatality uncovered possible evidence of criminal involvement in the man's death, according to the M.E.'s office, which declined to disclose the nature of those findings.

Fellow inmates told authorities the man had fallen out of his bunk-bed unconscious and did not respond to their attempts to rouse him.