DURHAM — A 21-year-old inmate at the Durham County jail was found unconscious in his cell and died Thursday, the Durham County Sheriff’s Office announced Monday.

Terry Demetrius Lee, who lived on Herbert Street in Durham, was arrested Wednesday by Durham police on charges of assault with a deadly weapon inflicting serious injury, discharging a weapon inside city limits and firing into an occupied dwelling or vehicle, possession of a firearm by a felon and resisting arrest.

An online listing of people booked into the jail on March 13 also shows a request from federal authorities to hold Lee, but Deputy Paul Sherwin, a sheriff’s office spokesman, said the nature of that request was not immediately available.

Jail officers found Lee unconscious in his cell about 2:20 p.m. Thursday and began cardiopulmonary resuscitation until Emergency Medical Services personnel got to the jail and began treating him, Sherwin said. But Lee never regained consciousness and was pronounced dead at the jail, he said.

Lee’s body was taken to the state medical examiner’s office, and the sheriff’s office is investigating his death, Sheriff Mike Andrews said in a statement.

“My thoughts are with the Lee family, and I’m very sorry for their loss,” Andrews said.

Lee’s bail had been set at $1,000,500 on all the charges.