Generate an explanation for the given claim using the provided supporting material from the paragraph. Please consider the following points while generating an output. 1) The claim will always have supporting proof in the paragraph, and the paragraph will have a clear point of view supporting the claim. 2) There can be instances where direct correlation to the claim is not available. Make use of the sentences in the paragraph to provide a corresponding output supporting the claim. 3) The explanation should be at least one and at most twelve sentences long.
Q: Paragraph: The Michigan Department of Health and Human Services says it's working with the Macomb County Health Department to investigate the illnesses at McLaren Macomb Hospital in Mount Clemens. The departments say six of the seven Legionnaires' cases have been reported at the hospital since mid-September. Both agencies are investigating the source of the disease and whether there are more infected people. The hospital is cooperating with the investigation and plans to increase water testing to look for any signs of the Legionella bacteria that causes the illness. Legionnaire's is a flu-like illness contracted when infected water vapor is inhaled. The elderly and people with weakened immune systems can be particularly susceptible. Claim: Michigan probes Detroit-area hospital's 7 Legionnaires cases.
A:
State health officials are investigating after seven people treated at a suburban Detroit hospital were diagnosed with Legionnaires' disease.