Authorities are investigating a growing Legionnaires’ disease outbreak on Manhattan’s Upper East Side by testing building cooling towers for the bacteria that causes the illness. Multiple outlets report that health department officials have sampled water from nearly 160 cooling towers in and around the affected area as part of an effort to identify a common source. Early reporting said at least 28 people have been sickened, and later reporting describes the cluster expanding as case counts rise, including a figure of 46 cases cited by ABC News. Outlets also describe the outbreak as unusual and severe, with officials and experts noting that Legionella’s impact is increasingly shaped by environmental conditions. The Guardian reports discussion from public health officials that climate change may be worsening exposure to the bacteria. While reporting indicates some buildings may be linked to the cluster based on preliminary testing, outlets emphasize that the exact source has not been definitively identified. Coverage also includes efforts by local media to map cooling towers in the neighborhood to help narrow which buildings may be connected to transmission.