(AP) — Authorities say a man in the Douglas County jail facing child pornography charges has died.

County officials say staff noticed at about 3:30 a.m. Monday that inmate Daniel Clement appeared to be unresponsive in his single-cell room. Officers called for medical help and responders tried to revive Clement, but he was declared dead.

The Douglas County Sheriff’s Office has begun an investigation into the death, as required by state law.

The 53-year-old Clement had been in the jail since Wednesday. He was facing six charges related to possession of child pornography.