An inmate in the D.C. jail has died as officials struggle to cool the sweltering facility during a heat wave.

Lester Irby, 70, collapsed inside the D.C. Central Detention Facility on Thursday, Department of Corrections (DOC) officials said. According to the paramedics who responded, he appeared to be suffering a stroke.

Irby was taken to a hospital, where he died.

DOC spokeswoman Sylvia Lane said Irby appears to have died of natural causes.

"We have no reason to believe that there is a correlation between elevated temperatures and the recent death of an inmate," Lane said in an email.

But lawyer Deborah Golden, who monitors conditions in the jail, said Irby's death is a reminder of poor conditions inside.

"It's horrible, but it doesn't surprise me. I think it was a matter of time," the director of the DC Prisoners' Project said.

Golden described oppressive heat inside the jail, which houses more than 1,200 people.

"It's a giant brick building. It functions like an oven," she said.

Jail officials acknowledge the cooling system in the aging facility is overworked.

"D.C. Jail is a 40-year-old facility, and with elevated heat levels, the air handling system has much more work to do," Lane said in an email.

The directors of the DOC and the D.C. Department of General Services visited the jail's housing units on Friday and have "engaged a contractor to improve the airflow and circulation systems," Lane said.

In recent days, the jail has set up large industrial fans, offered inmates shaved ice and cool drinks, let inmates take additional showers, and provided accommodations for inmates with special needs, officials said.

Golden said it's not enough.

"The giant fans are helpful in the common areas but they don't reach into the individual cells," she said. "The ice is limited in quantity. It's a small plastic cup of ice to take back to your cell that needs to last 24 more hours. It just doesn't."

An inmate inside the jail called News4 on Friday, after watching a 4 p.m. broadcast, and said officials found that at 5 a.m. Friday, his cell was 87 degrees.

For days, News4 has received complaints from inmates and their loved ones about conditions inside the jail as temperatures have hit the 90s.

D.C. officials have declared a Heat Emergency and encouraged residents to stay in shade or air conditioning.

An autopsy has not yet been conducted to determine Irby's cause of death. He was jailed after he was charged with assault with a dangerous weapon, court records show.

Leaks in the jail's roof forced the DOC to close a part of the jail earlier this year, as News4 reported.

Golden called for officials to consider the replacement of the facility.

"It's not repairable," she said. "It's probably time to think about building a new jail and to plan for it."

Irby's lawyer, Paul Signet, said there was "no sign of any physical problem" when they last saw each other.

"Mr. Irby was in good spirit when we met at the jail on Tuesday last. He was also in good spirit at a court hearing on Wednesday last," Signet said.

A story by a man named Lester Irby was included in the 2005 book D.C. Noir, a collection of stories "detailing the seedy underside of the nation's capital." The story, "God Don't Like Ugly," was written while its author was incarcerated.

The editor of the book, George Pelecanos, and a representative for the book's publisher, Akashic Books, both said they fear the Lester Irby who wrote the story is the same Lester Irby who died, but that they have no confirmation.