An assistant nursing manager at a New York City hospital, who told his family he believed he had contracted the coronavirus after being exposed at work, died Tuesday evening, his sister told NBC News.

The death of Kious Jordan Kelly, 48, was confirmed by Mount Sinai Hospital. It comes amid an escalating crisis in New York in which hospitals are faced with surging numbers of coronavirus patients and shortages of crucial medical equipment and protective gear for staffers.

Kelly suffered from severe asthma, said his sister, Marya Sherron, but she questioned whether his death could have been prevented and expressed alarm over the reports of inadequate protection for health care workers.

Kious Jordan Kelly, a 48-year-old assistant nursing manager at Mount Sinai Hospital in New York. Courtesy Mount Sinai Hospital

"There's only going to be more," Sherron said. "He's not the only one with asthma. He's not the only one with conditions who is going to work every day helping and fighting for people."

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Mount Sinai Hospital did not respond to specific questions about how Kelly was exposed to the virus, but it insisted that it has provided workers with the necessary protective equipment.

"This crisis is straining the resources of all New York area hospitals and while we do — and have had — enough protective equipment for our staff, we will all need more in the weeks ahead," a spokesperson said. "This crisis is only growing and it's essential that we not only have all the right equipment but that we come together to help and support one another."

In an earlier statement, the hospital described Kelly as "a compassionate colleague, friend and selfless caregiver."

"Today, we lost another hero," the statement added.

A colleague confirmed that Kelly had been working directly with coronavirus patients at the Mount Sinai West medical center.

"He was moving them, transporting them, going into their rooms," said the colleague, who asked to remain anonymous for fear of jeopardizing the person's job. "He used to do whatever he needed to do to decongest the emergency department or help the nurses out so patients wouldn't sit in the hallway exposing others."

"He paid the ultimate price for working too hard and caring too much," the colleague added.

Kelly was born in Chicago and grew up in Lansing, Michigan, his sister said. He was valedictorian of his high school and worked as a dancer for many years before becoming a nurse.

"He was born with a hole in his lung, and my mom talked about how she was told he wasn't going to live and he healed," Sherron said. "He wasn't supposed to be able to do a lot of things physically that he did, and we were always in awe. "

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The last time Sherron heard from her older brother was via text message. He got in touch on March 18, Sherron said, telling her that he had been moved to the intensive care unit at the main Mount Sinai Hospital and that he couldn't talk because he was on a ventilator. He sent her a photo and told her he would be OK and not to worry the rest of the family. Six days later, he was dead.

"He was the best. He was just the most giving, selfless person," Sherron said. "He would always find a way to make you smile."

Joseph Fuoco, the son of a former patient, described Kelly as an angel in a post on Mount Sinai's website, where he recounted how Kelly took care of his dying mother.

"He showed my mom and us empathy and compassion that helped us get through the weekend and what was to come," Fuoco said. "He went above and beyond and is an asset to the hospital."

Kelly's family, like the loved ones of any coronavirus patient, were barred from visiting him in the hospital because of the risk of transmission.

His sister said she's still wrestling with the fact that her younger brother died alone.

"I want his unit, the hospital and health care providers to get the protective gear they need," Sherron said.

CORRECTION (March 26, 2020, 6:35 p.m. ET): An earlier version of this article identified the nurse who died as James Kious Kelly. Kelly's sister said James was his middle name at birth but that he had legally changed his name to Kious Jordan Kelly. The article also misspelled the sister's first name. She is Marya Sherron, not Mayra.