CHICAGO (CBS) — A third Cook County Jail inmate has died after testing positive for COVID-19, officials said Sunday.

Nicholas Lee, 42, was pronounced dead Sunday morning at Stroger Hospital of Cook County, according to the Cook County Sheriff’s office.

Lee had been hospitalized since Monday, April 6, after testing positive for COVID-19, according to the Cook County Sheriff’s office. His official cause of death is pending autopsy, but preliminary reports say he died of cardiac arrest.

He was booked at the Cook County Jail on Oct. 31, 2016, where he was being held without bond at the time of his death on charges of including armed robbery and being an armed habitual criminal and armed robbery – as well as aggravated unlawful restraint, aggravated unlawful use of a weapon, aggravated battery to a peace officer, felony possession or use of a firearm, and resisting a peace officer.

The most serious charges carry prison terms of 6 to 30 years in prison.

An arrest report indicated that Lee was accused of robbing a man at gunpoint of $500 in cash, an iPhone, and jewelry. When police tried to arrest him, he fought them in an attempt to escape and injured an officer, the Sheriff’s office said.

He had a 9mm handgun with him at the time.

Lee has a history of felony convictions dating back 20 years for drug and gun offenses and for resisting and obstructing a police officer, the Sheriff’s office said.

Two other inmates have died after testing positive for coronavirus.

Leslie Pieroni, 51, was pronounced dead Thursday evening at St. Anthony’s Hospital, according to the Cook County Sheriff’s office.

He had been hospitalized since Friday of last week after testing positive for COVID-19, the Sheriff’s office said.

The first inmate to die of COVID-19 was Jeffrey Pendleton, 59, who was pronounced dead at Stroger Hospital of Cook County at 9:49 p.m. last Sunday.

As of 5 p.m. Sunday, there were 254 jail inmates with mild-to-moderate COVID-19 symptoms being treated at the jail’s Cermak Health Services, and 20 who were being treated at offsite hospitals.

A total of 32 detainees have been moved to a recovery unit, the Sheriff’s office said.

On Thursday, a federal judge denied the request for a mass release of inmates at the jail due to COVID-19 concerns, but ordered Sheriff Dart to implement new safety measures to stop the spread of COVID-19.

The jail has been called the single largest coronavirus hotspot in the country, but Dart claims their numbers are higher because they are testing more aggressively. He said the numbers also include 150 COVID-positive sheriff’s staff‚ some of whom don’t actually work inside the jail facility.

“They threw in employees who are police officers who have never been in the jail, clerks who have never been in the jail,” he said. “So that’s a bit of a problem. My 5-year-old would have nailed the math a little better than they did.”