Officials in New York City report five deaths linked to a Legionnaires’ disease outbreak, a form of pneumonia caused by Legionella bacteria. Multiple outlets report that investigators have not yet identified where the bacteria is coming from. City health officials are continuing efforts to pinpoint the source while monitoring cases and coordinating response measures.

Reports say the outbreak is centered on Manhattan’s Upper East Side, particularly around the Carnegie Hill and Yorkville neighborhoods. According to city Health Department figures cited across coverage, the outbreak has sickened at least dozens of people—one report places the total at about 67—with many patients hospitalized. Over the past several days, additional deaths have been announced, including a later confirmation of a fifth fatality.

While some reporting notes that officials believe the outbreak source may have been eliminated, the broader consensus across sources is that the origin is still under investigation. The city continues public health work to trace exposure and prevent further illness.