One hostage is dead and a second is recovering after authorities entered a building at a Delaware prison where inmates had taken staff members hostage.
Officials announced on Thursday that the building where the disturbance occurred at the James T. Vaughn Correctional Centre is now secure.
The prison is in Smyrna, about 15 miles north of the state capital of Dover.
Officials say that after authorities breached the building, one Department of Correction worker was found unresponsive and later pronounced dead.
The inmates took four corrections department workers hostage on Wednesday morning, prompting a lockdown of all Delaware prisons.
The inmates released one staff member in the afternoon and another on Wednesday night. At least one of those staffers had injuries that were not considered life-threatening.
The Delaware Department of Correction says 14 more inmates were released at about 12.30am on Thursday from the building where the hostages had been held and were being held elsewhere at the prison.
The news release said 46 inmates have been released from the building since the hostage situation began, including the 14 released early on Thursday.
The inmates told a local newspaper that concerns about their treatment and the leadership of the US had prompted their actions.
The hostage situation drew dozens of officers and law enforcement vehicles and prompted a statewide lockdown of all prisons.
A preliminary investigation suggests the disturbance began at about 10.30am when a correctional officer inside building C, which houses more than 100 inmates, radioed for immediate assistance, Delaware State Police spokesman Sergeant Richard Bratz said.
Other officers responded to help and the employees were taken hostage, he said.
Robert Coupe, secretary of the Delaware Department of Safety and Homeland Security, said authorities do not know "the dynamics of the takeover" or whether inmates had been held against their will.