A Westchester County child has died from an illness linked to COVID-19, marking the second known such fatality in the state.

Westchester County Executive George Latimer, who announced the death during a Friday afternoon press conference, did not state the age or gender of the child.

However, during the county executive's morning press briefing, Dr. Michael Gewitz, the physician-in-chief at Maria Fareri Children’s Hospital, said that a boy with a serious neurological complication had died but that doctors were further investigating whether his death could be attributed to the new illness.

Before Friday, there had been only one confirmed death, that of a 14-year-old in the United Kingdom, from the condition which is being called "pediatric multisystem inflammatory syndrome.” Resembling toxic shock syndrome and Kawasaki disease, the symptoms have included fever, a swollen tongue, rash, as well as stomach aches. Although some of the patients have required intensive care treatment, the disease has been described as highly treatable.

In New York City, Mount Sinai officials notified state and city officials on Friday that one of their young patients had died from the illness. Governor Cuomo later identified the individual as a 5-year-old.

"While it is concerning that children are affected, we must emphasize that based on what we know thus far, it appears to be a very rare condition," said Jason Kaplan, a spokesperson for Mount Sinai. "We encourage any parent who may have concerns to contact their pediatrician for a consultation. Mount Sinai and the healthcare community will continue to investigate and study this new variant in hopes of finding a solution to this rare condition."

Kaplan declined to say how many cases the hospital had reported to date, saying only that like other New York City hospitals, there had been "several cases."

New York City's Department of Health on Friday reported 20 known cases in hospitals. Across the state, 73 children have been hospitalized for the new disease, Cuomo said. Many of those children have tested either positive for COVID-19 or for the antibodies, suggesting a previous infection.

Westchester County has 11 cases to date, among children ranging from those in infancy to teenagers.

Gewitz said that symptoms among children can appear between two weeks to as long as two months after a coronavirus infection.

"This is not acute or sudden onset of covid disease necessarily," he said.

During his press conference, Cuomo said the state was investigating other cases.

“This would be really painful news and would open up an entirely different chapter,” he said. “Because I can’t tell you how many people I spoke to who took peace and solace in the fact that children were not getting infected.”