Given the task definition and input, reply with output. Given a paragraph, generate a claim that is supported by the given paragraph. 1) The claim must contain information from within the paragraph. 2) A sentence within the paragraph can be used as a claim. 3) The claim should not have contradictions within the paragraph. 4) The claim should be at most one sentence long.

It said Thursday that two of the four were patients at Advocate Christ Hospital in Oak Lawn within the past two months. The agency says it will visit the hospital this week to test its water and that the hospital is working with it to strengthen its water management. The agency says it has recommended the hospital inform patients and families about Legionella bacteria and work to identify other potential cases of the disease. Water containing naturally occurring Legionella bacteria can be aerosolized through cooling towers, showers, hot tubs, and decorative fountains and, when inhaled, cause Legionnaire's disease, which is a serious lung infection.
4 cases of Legionnaires' disease investigated at hospital.