New York City health officials have confirmed that legionnaires' disease has killed one person and sickened four others in a new community cluster in the South Bronx - just weeks after declaring a separate deadly outbreak on Manhattan's Upper East Side officially over. Because nothing says "crisis resolved" like a fresh crisis.

On Thursday, officials announced that the municipal health department had launched an investigation into the cluster in parts of Melrose and Morrisania, including ZIP codes 10451 and 10456. Sampling of cooling towers in the area has been completed, with testing under way at the city's public health laboratory. Previous community clusters have been linked to Legionella spreading through mist produced by cooling towers, and building owners whose towers test positive are directed to drain, clean and disinfect them - a sentence that should probably be printed on every HVAC maintenance contract in the five boroughs.

The department has also issued a health alert to providers, advising them to consider legionnaires' disease when evaluating patients with compatible symptoms. "Our disease investigators have confirmed five cases of Legionnaires' disease and are working quickly to identify and confirm any additional cases in the area. Sadly, one person has died, and our deepest condolences are with their loved ones," said a statement attributed to the city's health commissioner, Alister F Martin.

"I understand that New Yorkers may have heightened concerns following the recent Upper East Side cluster," Martin added. "We are taking immediate action. Community health workers will be canvassing the neighborhood. Anyone who lives, works, or has visited the affected area since late August and is experiencing flu-like symptoms should contact a health care provider as soon as possible."

For the uninitiated: legionnaires' disease is a form of pneumonia caused by Legionella bacteria, which can grow in warm water - especially in human-made building water systems including showerheads and sink faucets, hot tubs, large and complex plumbing systems, and cooling towers, according to the federal Centers for Disease Control and Prevention (CDC). The bacteria can also grow in a vehicle's windshield wiper fluid tank, with the CDC warning that they are more likely to thrive when the tank is filled with water rather than genuine windshield washer fluid. Yes, your car's questionable maintenance habits are now a public health footnote.

People can become infected by breathing in contaminated water droplets or mist. Nevertheless, New York City health officials say it is safe to use air conditioners, drink tap water and shower unless otherwise advised. Symptoms can include fever, chills, muscle aches and cough. The disease is not contagious and can be treated with antibiotics when caught early - which is the one genuinely reassuring sentence in this entire story.

The South Bronx investigation marks the second community legionnaires' disease cluster identified in New York City in recent months, after the Upper East Side cluster identified in July. Multiple community clusters in one season have previously occurred in the city, including two each in 2015, 2017 and 2018, and three in 2016, according to city officials. So if you're keeping score at home: this is not unprecedented, merely unwelcome.

The disease was named legionnaires' after a 1976 outbreak in Philadelphia, which largely affected people attending a convention of the American Legion, the war veterans' nonprofit organization. Nearly five decades later, it remains a reliable reminder that the buildings we live in are basically complex plumbing systems with opinions.