A 47-year-old Hilo man died today while in the custody of Big Island police.

The man was found unresponsive within a cell at the Hilo police cellblock at about 3 p.m., police said.

Fire/rescue personnel were summoned, but he could not be revived. He was pronounced dead at Hilo Medical Center.

The man had been taken into custody at 9:50 a.m. yesterday on suspicion of criminal trespass in the first degree and theft in the third degree. He had been unable to post $1,000 bail and was placed into a single occupancy cell, police said.

An autopsy has been scheduled to determine the exact cause of death.

An investigation into the death is under way, police said.

The man's name is being withheld pending notification of family members on the Mainland.