This post has been updated.

A city prison inmate has been charged with murder after correctional officers found his cellmate bloody and unconscious in their locked cell Tuesday morning.

Sylvester Smith, 46, is accused of attacking Darryl Warthen, 52, sometime before 7 a.m. Tuesday in their shared cell at the Philadelphia Industrial Correctional Center. Correctional officers found Warthen collapsed and bloodied in the cell, and medics declared him dead at the prison at 7:25 a.m. Sources initially told the Daily News that Warthen had been stabbed. But police spokeswoman Officer Christine O'Brien said today that Warthen died of blunt force trauma to his head, and investigators determined Smith allegedly used his hands to injure Warthen.

Smith now is being held without bail pending a May 19 preliminary hearing, according to court records.

Warthen had been jailed for months awaiting a mental-health status hearing in two cases: a 2012 burglary and a 2004 criminal-trespassing incident, court records show. Smith was transferred to PICC Monday to await trial in a December aggravated-assault case, records show.

PICC houses 971 medium- and maximum-security adult inmates and 38 juvenile boys on State Road, Hawes said.

In a review of city inmate deaths last year, the Daily News found that jail deaths have crept upward in recent years, with 15 in 2012 and 2013 and 14 last year, compared with the decade's low of eight in 2010. Most were ruled natural, the result of health issues. Warthen, the seventh inmate to die in custody this year, is the city's first inmate murdered behind bars since June 2011, when Earl Gene Bostic got stabbed to death at the Curran-Fromhold Correctional Facility, records show.