The 10-year-old hockey player from New Canaan, Connecticut, is depicted in photographs suited up and looking fierce on the ice. His coaches said he "captivated, entertained and kept us on our toes," according to a GoFundMe page.
His mother said "he was like an ox" - strong and never sick.
"Ten years of health," Mimma Mallozzi told Time this week. "The kid never had a problem."
So it was perhaps little surprise that even after he came down with the flu, Nico still wanted to accompany his team to a recent tournament in Buffalo, even though there was no chance he would play.
But during the trip to support the RoughRiders, his mother said, Nico's health deteriorated.
"He progressively got worse," she told Time. "I didn't like the way he looked."
He was taken to a hospital in Buffalo, amid a particularly harsh flu season in which the entire continental United States is experiencing widespread influenza. By Sunday, the Mallozzis had decided to head home. But Nico's condition worsened, so they called 911 while driving through the Catskills.
The boy was rushed to another New York hospital - and was confirmed dead before the end of the day, according to the New Canaan News.
New Canaan Director of Health David Reed told the newspaper that a medical examiner in New York determined that Nico died of sepsis resulting from pneumonia, a complication of influenza.
Reed declined to comment Thursday, and the Mallozzi family could not immediately be reached for comment.
But his mother, Mimma Mallozzi, told Time, "He was just a carefree, fearless, easygoing child, full of energy."
Her son's sudden death, she said, "is actually a nightmare."
A nasty flu season is in full swing across the United States, with a sharp increase in the number of older people and children being hospitalized, according to the Centers for Disease Control and Prevention.
"Flu is everywhere in the United States right now," Daniel Jernigan, director of CDC's influenza division, said last week. "There's lots of flu in lots of places."
According to earlier reporting by The Washington Post:
"The main culprit for this harsh flu season is the predominant strain, H3N2, which causes the worst outbreaks of the two influenza A viruses and two types of influenza B viruses circulating. Seasons where H3N2 dominates typically result in the most complications, especially for the very young, the elderly and people with certain chronic health conditions, experts say.
"Even though flu activity has probably peaked, the forecast for next three months is grim."
New Canaan Public Schools Superintendent Bryan Luizzi said Nico Mallozzi, a fourth-grader, was diagnosed with influenza B.
Since the start of flu season in October, nearly 6,500 people have been hospitalized - the highest number of those were among adults older than 50 and children younger than 4, according to the most recent data from the CDC.
The agency reported that since the beginning of the year, seven children have died of influenza and related complications. In total, the CDC said, 20 children have died during the current flu season.
Recently, a 21-year-old aspiring personal trainer reportedly died of influenza-related complications - organ failure resulting from septic shock.
Then a marathon runner.
And a mother who reportedly caught it from her children.
The lesson, experts say, is the flu can hit anyone at anytime - and it's important to prevent disease as well as treat it promptly and appropriately.
Although the CDC states that "most people who get influenza will recover in several days to less than two weeks," Brendan Flannery, an epidemiologist with the CDC's influenza division, said it can be deadly. However, Flannery said, with the fatal cases of flu, it's often the complications associated with influenza that lead to death, such as bacterial infections, airway issues and organ failure.
"These cases are reminders the flu can be fatal and reinforce the need to prevent the flu," he said.
In many cases, Flannery said, children who had severe cases of the flu had not gotten the vaccine.
Flannery said the influenza vaccine along with proper hygiene and then, when needed, prescription antiviral medications used to treat the flu, such as Tamiflu, are the best ways to combat it. In fact, he said, there is so much flu activity that the CDC recommends doctors treat suspected cases of influenza - and not wait for test results.
Reed, the New Canaan health director, told the local newspaper that Nico's brother also tested positive for the flu.
"This has been one of the worst flu seasons and I think it will continue until March," he said. "If you're not vaccinated, get vaccinated now. The flu season varies every year, but a vaccine can mitigate the symptoms."
Nico's mother told Time that the flu caught her 10-year-old son "off guard."
She then warned other parents: "You have to be aware of your child."
"There are no words to describe the loss we feel," the family said in a statement on the GoFundMe page, which had raised more than $145,000 by late Thursday. "But we are so appreciative and grateful for the outpouring of support from so many in our hockey family and local community."
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
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