A 58-year-old man who died at Sing Sing Correctional Facility this week was confirmed to have COVID-19, according to an employee at the Westchester medical examiner's office.

Juan Mosquero, 58, died March 30th, according to records from the state Department of Corrections and Community Supervision.

On Thursday, an employee in the Westchester county medical examiner's office, who declined to give his name, told Gothamist/WNYC that Mosquero has tested positive for COVID-19.

His cause of death has not yet been determined.

Mosquero’s death is the first known death in the state prison system in which the individual was confirmed to have COVID-19. In NYC's jail system, there have been no known virus-related deaths. Mosquero, who was convicted in Queens, had been incarcerated since 2012 for sex offenses, including child sex abuse.

Before he died, men incarcerated at Sing Sing in Ossining, New York had been fearful of the virus's spread in the facility.

"This is not a place where you show fear," said John J. Lennon, a 42-year-old man serving 28 years to life in Sing Sing who also hosts a podcast, "This Is A Collect Call From Sing Sing." "But I've seen it now more than ever before. This idea of going out in a stinking prison cell gasping for air—it's frightening to even the toughest of guys."

"Men have to go to the mess hall, men have to get their insulin, men have to leave your cell, and when you're walking by, you're essentially walking by scores of cells depending on where you look," Lennon said. "Medical’s not doing anything anyway. They're telling guys to go back to their cells 'til their fever gets higher."

Listen to Gwynne Hogan's report on WNYC:

Lennon said he believes the department is not testing enough people.

As of Tuesday, there were 14 people in DOCCS custody who had tested positive for COVID-19 of about 43,000 incarcerated statewide, the department said. Another nine parolees of 35,000 currently out on parole had also tested positive.

New York State Correctional Officers and Police Benevolent Association's vice-president of the southern region, David Luther, said at Sing Sing alone, there were six positive cases of the coronavirus among inmates. A dozen were quarantined. About 29 officers at the facility, of 700, had also tested positive. Another 47 were also quarantined.

Several detainees at Sing Sing told Huffington Post that Mosquero died of flu-like symptoms after he was quarantined on March 20th. He was a law library clerk and was remembered as "funny, kind hearted, quick witted (even with limited english) and hardworking," HuffPost reported. In mid-March, an employee tested positive at Sing Sing.

DOCCS did not immediately respond for comment. The Governor's office, which faces pressure from advocates to grant clemencies to older prisoners and those nearing the end of their sentences, also did not immediately respond for comment.

DOCCS previously said that a “pandemic flu protocol” has been modified within the prison system for the COVID-19 outbreak. The department says soap and water are “readily available” in the facilities and has implemented measures like suspension of visits, suspension of internal transfers except for health or safety purposes, and displaying posters with safety tips, and providing hand sanitizer dispensers. (Previously, hand sanitizer was barred from state prisoner use, though the Governor had been using inmates’ to fill NYS-branded bottles with hand sanitizer under a prisoner work program that pays an average of 65 cents an hour.)

Governor Andrew Cuomo ordered the release of about 1,100 parole violators in local jails last week, of which about 570 have been released, according to DOCCS. 140 of those were released from Rikers Island in NYC, where the virus has spread to more than 350 Department of Correction employees, health personnel and inmates.

In a letter to DOCCS and the Governor's office this week, the Legal Aid Society said their clients have reported “insufficient access to medical attention and an inadequate supply of hygiene and cleaning products.”

The organization demanded the release of four people in state prison facilities identified as at-risk of COVID-19 due to medical issues and near the end of their sentences or with upcoming parole hearings. Legal Aid also called for the state to identify others among the tens of thousands in similar circumstances.

Among those Legal Aid identified include a 60-year-old woman serving a two year sentence at Taconic Correctional Facility in Bedford Hills, New York.

She suffers from rectovaginal fistula, which she developed after treatment for rectal cancer, according to the letter. Her symptoms may result in the need for surgery to avoid the risk of developing sepsis. Her parole release is slated for April 28th, after she served a sentence for selling and possessing drugs. While in custody, she completed an education program, alternative violence program, and substance abuse treatment program, according to the letter.

“It makes little sense for the Department to risk [her] health by holding her another 28 days,” a staff attorney for Legal Aid, Stefen Short, wrote in the letter.