A 5-year-old boy has died of a rare inflammatory condition possibly linked to COVID-19, the first such death in New York, Gov. Andrew Cuomo said Friday. Also, some New York City parks will see stepped-up policing to stem the spread of the coronavirus, Mayor Bill de Blasio said. And 2,500 members of a “test and trace corps” will be in place by early June to combat the virus, the mayor said.

While children have been shown, so far, to be far less likely to suffer severe harm from the coronavirus, there is growing concern that a rare complication might be causing some to experience swollen blood vessels and heart problems.

At least 73 children in New York have been diagnosed with symptoms similar to Kawasaki disease — a rare inflammatory condition in children — and toxic shock syndrome.

The death of a 5-year-old boy Thursday at a New York City hospital is sad news for New Yorkers who believed children were largely unaffected by the coronavirus, Cuomo said.

“So this is every parent’s nightmare, right? That your child may actually be affected by this virus," the Democratic governor said. "But it’s something we have to consider seriously now.”

Children elsewhere in the U.S. have also been hospitalized with the condition, which was also seen in Europe.

A spokesperson for The Mount Sinai Kravis Children’s Hospital, which treated the child, expressed condolences to the family and stressed that the condition has been, thankfully, rare.

“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," Mount Sinai spokesperson Jason Kaplan wrote in a statement. “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.”

There is no proof yet that the virus causes the syndrome. At least 3,000 U.S. children are diagnosed with Kawasaki disease each year. It is most common in children younger than 6 and in boys.

Symptoms include prolonged fever, severe abdominal pain and trouble breathing.